What are the requirements of applying for a visa to china for a workshop

Do you mean to apply for a work visa to China? if yes, you need to prepare for following documents:
1. Original invitation or confirmation letter (used to be called Visa Notice) from an authorized government organization like the local foreign affairs office, ect. in China;

2. Registration Certificate of Foreign Enterprises Permanent Office in China/Alien Employment License of

the P. R. China/Working Permit by the State Administration of Foreign Experts Affairs, China;

3. Physical Examination Record for Foreigner ;

4. Supporting letter from your organization;

Basic requirements are your passport, application form and photo.