Jackin' Chan is a mission in GTA Chinatown Wars given by Chan Jaoming.
When you arrive at Chan's garage one of his men tells Huang that he's been kidnapped. You'll need to rescue him. Head over quickly to the docks at BOABO, and you'll find two Irish American Killers gang members setting Chan's car on fire with two oil tankers and Molotov Cocktails. You'll need to extinguish the fire out quickly or Chan will die. Luckily, there's a nearby firetruck that help. Steal it, and extingish the fire. Then, get into Chan's car and drive him back to East Island City. Watch out, some thugs will be chasing you! However, once you get back to his garage Chan blames you for everything, and doesn't want you in any of his work anymore.
Shortly after this, another competitor to the race for replacing Hsin Jaoming, Zhou Ming contacts you about doing some work for him. Head over to his club in East Island City, but you need to bring 20 bags of Weed as a payment to him.