BEWARE OF SPOILERS. Due to the nature of the show, with its many Walking Spoiler characters, twists, and turns, the only spoilers whited out are those for the current season "24: Live Another Day". Proceed with caution!
The Chinese president during the events of Live Another Day.
- General Ripper: At first he seems to be this, as he shows virtually no interest in listening to Heller's (and as we're later told, Alastair Davies's) explanation of how Cheng Zhi was responsible for sinking a Chinese aircraft carrier and immediately declares all-out war on the U.S., even going so far as to deploy nuclear weapons to cripple America's satellite surveillance network within the first few minutes of the war. However, a Chinese Embassy staffer spoken to by Audrey later that episode implies that he's doing so more to appease the hardline elements in his party.
The Chinese consul in Los Angeles.
- Small Role, Big Impact: His death results in a massive feud between Cheng Zhi and Jack Bauer.
The deputy Chinese consul in Los Angeles.
An associate of Audrey Bodreau who works for the Chinese Embassy in London.
Head of Security at the Chinese consulate in Los Angeles. When Consul Koo Yin was killed during a raid on the consulate, Cheng was appointed by Deputy Consul Su Ming to lead the investigation. Cheng eventually learned from Howard Bern that Jack Bauer was behind the attack on the consulate and captured him at the end of Day 5. He was responsible for the torture of both Bauer and Audrey Raines. His acquisition of the Russian FB subcircuit board sparked an international incident between the United States and Russia.
- Arch-Enemy: Has become this to Jack as much as Nina and Logan are. Audrey also has a special hatred in her heart for Cheng Zhi. The writers even have Cheng Zhi practically emulate Nina in the final episode of Live Another Day, with his ordering the execution of Audrey, sending Jack into a rage and allowing for Bauer to decimate Zhi and his men with all the fury that he inflicted on the Drazens back in Season 1.
- Big Bad Duumvirate: With Phillip Bauer during Day 6, once Fayed and Gredenko are taken out. And with Anatol Stolnavich in Day 9.
- Character Death: After hounding Jack for Days 4, 5, 6 and 9, Cheng finally meets his end when Jack decapitates him.
- The Chess Master: What makes him incredibly dangerous is the way he utilises his resources during operations. Most of his plans end up with him successful and alive while those trying to stop him either meet failure or wind up dead. A prime example is the hostage exchange in Day 6 where he leaves a heavily armed team of CTU agents in the dust through the contingencies he put in place.
- Crazy-Prepared: During Day 6, when his hostage exchange is interrupted, his sniper team lay down sufficient covering fire for Cheng to evacuate the area, when CTU deploys a helicopter, one of his men breaks out a rocket launcher to blow it out of the sky and when CTU try track him electronically his convoy splits up in different directions. He continues to be this in Day 9, assassinating the Chinese foreign minister's daughter and her bodyguards to prevent Audrey from preventing the war he's trying to cause.
- Curb Stomp Cushion: At the end of Day 9, he loses his climactic fight with Jack pretty quickly, but he manages to show off some pretty impressive kung fu moves before getting beaten to a pulp.
- Defiant to the End: He does not beg to Jack, probably knowing it won't do any good.
- Disproportionate Retribution: He feels China abandoned him so he wants to see it utterly wiped out.
- The Dreaded: Jack, Audrey and President Heller all freak out when They find out he's involved in the events of Day 9.
- Evil Counterpart: Like Jack, he's a highly efficient agent who commits some morally questionable acts in the name of getting the job done. While Jack has certain lines even he won't cross and the harsher decisions he's forced to make are never ones he does so lightly, often being shown to weigh heavily on him, Cheng is an out and out sociopath who can and will play dirty any way he gets without a hint of remorse. Gets taken Up to Eleven as of Day 9. By Live Another Day both men have gone from being top agents for their respective governments who did what they thought was the best for them to ultimately being declared to be traitors and abandoned for committing extremist acts. Despite his own disillusionment, Jack's sense of right has been helping him working his way toward redemption, coming out of hiding to protect Heller even with his own freedom on the line rather than let millions of people die. Cheng on the other hand now sees his all of China as his enemy for daring to turn its back on him, ultimately choosing to attack it in addition to the U.S.
- Evil Is Petty: Launching an attack on his own country to start World War III because its government abandoned him for extremism and criminal actions is... a bit excessive.
- Evil Sounds Deep: In the Italian version he speaks in a very gruff and deep voice. Quite sinister.
- Far East Asian Terrorists: At the end of Day 6, he was jailed for committing extremist actions, including trying to provoke a war, in the name of helping his home country. But after he was broken out of prison, he becomes a traitorous terrorist.
- Faux Affably Evil: He always has a polite tone that brimes with cruelty or condescendance.
- Final Boss: Of the series as of Live Another Day .
- Giant Space Flea from Nowhere: Multiple times now, most notably, Day 5 where he kidnaps Jack Bauer and Live Another Day.
- Greater-Scope Villain: All Day 9 happens because of him, until he steps in to achieve his goal
- Hijacked by Ganon: Was the one who originally commissioned the override device that was stolen by Margot Al-Harazi, and reclaims it by force from Open Cell to launch a US nuclear sub attack against a Chinese carrier.
- Implacable Man: With the resources he has, he's able to conduct complex operations such as kidnappings and hostage exchanges while leaving American law enforcement in the dust.
- I Have Your Wife: He pulls this on Jack.
- It's All About Me: He wants to start a nuclear war that will likely kill billions because he's pissed that China didn't try to get him out of prison.
- Jerkass: And that's one of the nicer things you can say about him.
- Knight of Cerebus: Things were bad enough in Day 9, and they get a whole lot worse when he shows up.
- Lack of Empathy: When you're willing to start World War III over a personal vendetta, it's fair to say consideration of others isn't your strong suit. Not to mention torturing Jack for the better part of 2 years(and later Audrey)
- Motive Decay: He originally starts off as a Well-Intentioned Extremist who goes to extreme lengths to get justice for the Chinese consul accidentally killed in a raid led by Jack Bauer, but in season 6 turns into a terrorist wanting to start a war, kidnaps and tortures the daughter of a former Secretary of Defense to insanity, and helps Jack's evil father kidnap his grandson. All this in China's interest, of course.And by Live Another Day, he is willing to hijack US military programs to open fire on his own country to start a war between the two.
- Never My Fault: It seemingly never occurs to him that maybe his getting abandoned by China was his own fault for his terrorist actions.
- Off with His Head!: After video proof of his capture has been filmed and sent to the Chinese government, Jack decapitates him in revenge for Audrey's death.
- Omnicidal Maniac: The only 24's villain to actually reach this category. He wants to start a nuclear war that could potentially kill billions.
- Overarching Villain: Since season 4, he has been an on and off villain alongside Charles Logan.
- Red Right Hand: His right side of his face is covered with a burn scar he got from an explosion in the Day 6 finale.
- Revenge Before Reason: His motivation for trying to start a war that would result in the deaths of millions, maybe even an all-out nuclear apocalypse? His country abandoned him.
- Sanity Slippage: Being abandoned by his country did not do wonders for Cheng's mental health
- Shadow Archetype: To Jack on Day 9, being what, with their differences, Jack could have become if Chloe hadn't talked him out of his vengeance spree at the end of Day 8.
- The Social Expert: He notices right away CTU is bullshitting him about the consulate infiltration.
- The Sociopath: Oh sweet mother of heaven yes. Even before his own country labelled him a traitor he didn't care whose lives he ruined in order to get his job done, and after being apprehended while working with a known criminal like Philip Bauer, he legitimately thinks his government would stick by him regardless of his actions due to how much of a loyal enforcer he's been, which they ultimately didn't. And then after going rogue, he's willing to start a war which would have resulted in the deaths of millions of people to settle his own petty grudge against China, even though it was his own damn fault that the country turned his back on him.
- Sudden Name Change: In his first appearance during Day 4, he was referred to as "Cheng Gao." When he reappeared a few episodes later in the season he now had his more familiar name, and it stuck for the rest of the series.
- Torture Technician: He's an absolutely ruthless one. After two years hit him, Jack is a broken shell of a man and it takes Audrey years to recover from her experiences with him.
- Villain Has a Point: He does have a point thinking the Chinese are ungrateful bastards for abandoning him when he failed, despite him being backed by the Chinese government. His reaction to it, on the other hand, is wrong at every level.
- Villain Respect: He is very reserved, but his word indicate a certain level of respect for Jack after torturing him for 20 months and getting absolutely nothing from him. He had no reason to say that to Bill, but he still does.
- Well-Intentioned Extremist: What he started off as prior to Motive Decay.