how to get business visa for a Nigerian?

Nigerian citizens need to submit the following requirements to China embassy in Nigeria to obtain a business visa:visa application form, passport and its photocopy, passport photo, "Invitation Letter of Duly Authorized Unit" or "Confirmation Letter of Invitation", a formal introduction letter from your company to tell your identity, the purpose of visit to China, and supposed duration of stay in China, original and copy of your certificate of incoorporation, hotel reservation and round-trip air ticket, a list of requirements you've submitted.