what are the requirement we may need to get the China visa?

To apply for a China business visa, you should prepare the following documents:
1. Original passport with than 6 months validity left and sufficient blank visa pages
2. One truely completed Visa Application Form attached with a recently-taken passport photo downloaded from the official website of the China Embassy in UK
3. Letter of invitation from a company or institution in China included the full name and passport number of the invitee as well as the purpose and duration of the visit or an Invitation letter of Duly Authorized Unit or a Confirmation letter of Invitation issued by an authorized unit in China suas as Chinese government departments, companies and social organizations authorized by the Chinese Foreign Ministry.
4. if you are not UK passport holders, your original and a copy of permanent residence or work permit with a validity of at least half a year should also be provided.
The China Embassy may ask for additional documents, So please contact the foreign affairs office of the province, autonomous region or municipality directly under the Central Government where your host is located to know about this first.