Thank you for your question.  Sorry for the delay in responding, but I was trying to research your question, and locating information on reptiles in China can be difficult.  I contacted a PhD student who is doing research on Chinese snakes, and he just got back in touch with me on the identity of your snake.  It is commonly referred to as the big-eyed ratsnake or big-eyed racer (scientific name: Ptyas dhumnades). It is non-venomous.

This snake can attain a length of 220 cm (a little over 7 feet).  It can be found in grassland, woodland and agricultural habitats. It has a varied diet consisting of fish, lizards, frogs, other snakes, birds and mice. It is one of the fastest snakes in Asia.  It is generally a nervous snake and is known for its quick, erratic movements when cornered.

It is reportedly used in Chinese medicine as a treatment for leprosy and other general ailments.

Here's a link to a site with additional information and photographs:
http://www.snakesoftaiwan.com/Ptyas%20dhumnades/species_ptyas_dhumnades.htm

Hope this information helps, and thank you for using Ask an Expert.

Jim