i would like o visit china what document i have to apply for my visa

Is your purpose to China for business? if yes, you need to provide an invitation letter issued by the authorized government departments/companies/units in China, and Visa recommendation letter from your company if any. Other documents needed are your passport, application form, photo, bank statements, round-trip air tickets booking and hotel reservation.

Dear sir i am have a business in nepal i import from thailand. i did not know any company in chaina but i would like to search some business in chaina there for i need it could you pls tel me which way i will get business visa from nepal.
Gyawali

Or you can try to apply for a tourist visa instead with invitation letter from a China travel agency.