Important advice: Do not believe advertisement easily!

The most important thing is, you must know more details of the background about your employer, before you go to China.
Does the employer really do anything for you (including stay & working visa)?
Does the employer really have the ability to pay your salary & benefits on time, as promised?

Some employers in China, whom have no license for hiring foreign teacher, still hope you will work for them. They can not apply for a working permit for you, so you will have trouble if your traveling visa expires. Usually, your employer will tell you to leave China for a few days, or go to neighboring area such as Hong Kong, Macao, Vietnam, you need to extends your traveling visa, then back to China to continue working for them. In China, it is illegal if a foreigner has a job without a working visa or work permiting. If the government found you illegally working in China, the law will punish your employer & you.
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Some employers like to promise you some good benefits & salary when they sign a contract with you, but if your employer has not enough students they can not pay salary & benefit on time. If you are working without working visa your job's rights will be hurt. That happens often in China.
We suggest you must think of these problems before you choose an employer.

If you need help, you can contact: support@abroadchina.org
or visit http://www.abroadchina.org/person/faqs.asp