Cheng Zhi on Day 6
|Portrayed by||Tzi Ma|
|Seasons||4, 5, 6|
|First appearance||Day 4: 3:00 AM – 4:00 AM|
|Last appearance||Day 6: 5:00 AM – 6:00 AM|
Cheng Zhi was the head of security at the Chinese Consulate in Los Angeles. When Cheng discovered that Jack Bauer lead the raid on the Consulate that resulted in the death of their Consul, he had Jack captured and taken to China at the end of Day 5. On Day 6, his interest in acquiring the FB subcircuit board sparked conflict between the US and Russia.
 Day 4
Cheng Zhi is the director of security for China's Los Angeles Consulate. Lee Jong, a scientist with who worked with terrorist Habib Marwan, took refuge in the Consulate building. When the Consulate refused to give up Lee Jong, Jack Bauer leads a team into the consulate to apprehend him. In the raid, the consulate is killed by friendly fire. A member of the team was caught on video camera. Cheng Zhi apprehended the man illegally and got him to reveal that Jack Bauer was the leader of the team.
Cheng Zhi then contacted President Charles Logan to arrange to have Jack brought into Chinese custody to be put on trial. Walt Cummings, Logan's Director of Security is worried that a man with the knowledge of Jack Bauer could compromise many things if given to the Chinese. Therefore, he arranges for Jack to be killed. Jack eventually fakes his death to evade the Chinese and his own government.
 Day 5
At the end of Day 5, Cheng Zhi appears again. One of Cheng Zhi's men approaches Jack Bauer and tells him that he has a call on a house phone. This is actually a sting in order to apprehend Jack Bauer. Jack asks Zhi just to kill him. Zhi replies that Jack is far too valuable to kill him.
 Day 6
- Cheng is one of only two villains to survive three seasons and to remain alive as of the present, along with assassin Mandy. He and Mandy are also the only two villains to appear in two separate season finales. However, Cheng is in custody and Mandy is not.
- During his first appearance in Day 4: 3:00 AM – 4:00 AM, Cheng introduces himself to Michelle Dessler as Cheng Gow (or Dao). The name was first changed in the "Previously on 24" segment in Day 4: 5:00 AM – 6:00 AM.