what is the average pay an hour for english teacher in china.?

This much depends on which city you are in and whether you're teaching kids or business people. Typically I would imagine around 4000/month for a laowai in the countryside to 15000/month for someone with a good deal in a first tier city.

4000 what, YUAN? Like hell it is. Listen, Chinese schools would rather pay for a Chinese university graduate who studied English than an English-born to teach. 15000? What are you imagining, the monthly salary of a manager in an international corporation?

It's like investment opportunities, don't think you're the first one who thought about this.

China's status in world has attracted many people in thinking going to China and finding an English-teaching job would be easy-peasy, only to find there are already many westerners there, and the schools' standards of hiring have increased, to the point they prefer those who:

1 - Have a proper teaching certificate

2 - Have basic knowledges in Chinese, at least can communicate a little with it.

3 - Even better than 2, have someone who has stayed in China for years and can correctly translate between the two languages, and even speak fluent, no-accent Chinese like local-borns.

4 - Local-born, local-educated Chinese who studied English.

Now you might wonder why would they prefer a Chinese who studied English, than a handsome fellow like you who's born speaking it? Well, because local teachers have more experience with China's education system, which is quite different than what you would imagine, and thus the schools think if the teacher have a good knowledge of the educational system, they can teach the students about what they need to pass exams more efficiently.

See? Lots to consider, if you have more queries put it in Additional Infos and I'll try to answer them.