Visa to China

1. For some it is possible to get a tourist visa for more than 30 days, but it is rare now.
2. Business visas vary depending on the country. You need an invitation from a Chinese business and proof of your business and funds. In some cases, you may also need a copy of the Chinese business license as well as other documentation.
3. Working visas cannot be obtained by foreign individuals. They are obtained through businesses in China that are certified by the government to hire foreigners. The price depends on the nationality of the foreigner. To begin the process you should be invited by a Chinese company to obtain a visa at the Chinese embassy in your home country, then you can convert the visa upon entrance into China.

This is only what I have seen and understand. Rules change on a daily basis, so some of this may not apply to your situation. If you ask the Chinese embassy, you will probably get a dozen different answers.