I have a pet theory for what you are asking.  In China, basically, you do have a non religious society.  The "moral" taboos or standards present in Western societies do not exist here (but others do exist within the same subject).  As a result, ladies in general do move forward at a faster speed than their western counterparts, and that makes flirting almost nonexistent here. 

Once the Lady, in her mind, decides she likes you and that you are OK, for them the next logical step would be to be with you totally, no intermediate steps required.  It is, in a way, like either black or white, no gray in between.

Maybe I am totally wrong, but that is how I explain in my mind the lack of flirting going on here.

I guess their flirting is when you're walking down the street with them and they're leaning into you so much to the extent you may fall over.

Chinese girl: Hello, I haven't seen you before. How are you?

Chinese boy: Hehe, fine thank you, and you?

Chinese girl. I am fine too. You are nice. Do you want to be my boyfriend?

Chinese boy: I thought you'd never ask.

Maybe they don't flirt a lot before dating, but I see a lot of young couples flirting with each other. I don't know what else to call it. Maybe they are too shy...that's always their excuse for everything. Maybe it's a personality trait. My friend Rose can be very flirty (unintentionally). She is an outgoing person, unlike most Chinese girls I have met. You also have to remember that if a boy and girl are alone together, people will assume that they like each other. Besides that, all the normal signs of flirting are probably just interpreted as being friendly.

i think it has more to do with the guys. women need to be comfortable and maybe for the guys to start the flirting. i have flirted with co-workers no problem

I once went with some of my former students (4 girls and one boy) to a disco (my first time to one in many years) and one of the students was REALLY putting on the moves on the boy. She was dancing in front of him, playing with her hair, and looking him in the eye. And the guy? He was playing a video game on his phone! Occasionally he would look up at her, smile and go back to his game.

Finally, unable to stand it any longer I told him that she liked him. He said "I dont think so." Upon further prodding , he felt that she just liked to dance.  I tried and TRIED to get him to ask her to dance but it was no go until I made a bet with him. That if she turned him down, or laughed at him, I would treat him AND his roomates (all 7 of them) to dinner and beer and would pay the whole bill.

Well, THAT worked. He asked her to dance and she almost ripped his arm off dragging him to the dance floor while he had this "deer caught in the headlights" look.

I guess that boys at least, college age ones are just cluless... 

Now I got to know why I don't want to find a Chinese boyfriend. Because they don't know how to flirt. How poor we are...  The only fun was skipped...