Enter 'volunteer teaching jobs in China' in any search, and you'll get plenty adverts. Here's one from Yahoo:

https://search.yahoo.com/search;_ylt=Ar4yMqY6JxnuShsPXcD4iaybvZx4?fr=yfp...

Volunteer to do what?

Teach?

Industrial Intern?

Reporting?

Disaster Relief?

It would be helpful to know what it is you would like to do before recommending a resource that you can apply to.

If it is voluntary teaching you are looking at, I would recommend that you are careful what you sign up to. There are more than a few people in China that will think nothing about taking advantage of your generosity to line their own pockets. The money that is saved by not paying you a salary may end up not where you wish it to. You may be well advised to take a payed teaching position and donate the salary to whatever cause you wish to support. Even that is no guarantee that the money will be used in the correct way but at least you have a semblance of control.

China Development Brief has a jobs section and a volunteer/ interning section. The organizations advertise directly, so you don't need to pay money to volunteer. It has Chinese and English versions, www.chinadevelopmentbrief.cn or www.chinadevelopmentbrief.org.cn

Hi, guys. Sorry for the confusion. I do not mean to find a teaching non-pay job in China. I have a job and some holidays. I would like to travel around China a bit and also help some short-term projects or local group if needed. I already knew that the sponsors would charge money for this kind of volunteer work or working holidays which I think reasonable because the lodging and meals would be included. What I would like to know is where I can find a reliable sponsor website of meaningful projects. 

THX!