Vegetarianism has an odd place in Chinese culture. On one hand, Buddhism clearly values the ethical treatment of animals (particularly Theravada Buddhism, the Southeast Asian variety). On the other hand, Chinese cuisine is terribly veggie-unfriendly. Even if a dish doesn’t contain “meat,” it is usually flavored with some sort of meat like oyster sauce (ho yow), shredded meat (yok soong), or dried shrimp (ha mai). Even pastries are often made with lard. One thing I do appreciate is that Chinese people use every part of an animal (even chicken feet, which we called E.T. fingers growing up). Looking back I think this is one of the things that makes it easy to stop eating meat at 13. I definitely took a lot of heat at the time from relatives and family friends. My guess is that meat is seen as something that is valued because it is hard to come by; one should appreciate it and not reject it. Especially if you’re a pretentious 13 year old.
There are two types of vegetarianism that I know of– tzai (like “chai” but with a “tz” sound) and so. Tzai is less restrictive and can include seafood. This has been rationalized to me as being a difference between animals that bleed and do not bleed (although I’m pretty sure fish bleed). Many Chinese would consider a vegetable dish with oyster sauce tzai. So is more restrictive– no fish or seafood, no meat-based sauces. Not sure about eggs and dairy (Chinese cuisine doesn’t include much dairy so this rarely comes up).
The good news is that Chinese food companies also make a variety of fake meats that come canned, frozen, or dried. They are wheat gluten, rice, or soy-based and for the most part do an excellent job of replicating whatever they’re supposed to represent. I dare say they’ve turned it into an art form.