please explain and documents required for visit for business visa to China

In order to apply for a China business visa, you need to provide original passport and a photocopy of its pages with personal information; A fully completed Visa Application Form with signature; An original letter from the your employer. It should contain your name, nationality, occupation, purpose of the visit, the planned date of entry and financial conditions; An invitation letter from the Chinese side (original or a photocopy/fax is also ok); A passport photo with white background.
Sometimes, you may required other additional documents if consular officers deem necessary.