You need following documents for visa applications to China:
1. One completed Visa Application Form of the People's Republic of China with a recently taken passport photo stuck on it; and photocopies of passport data page and all the Chinese visas if any.
2. One formal introduction letter from your company to tell your identity， the purpose of visit to China, and supposed duration of stay in China.
3. The original and one photocopy of ID card.
4. The original and one photocopy of certificate of incorporation.
5. Hotel reservation in China and round-trip ticket between Nigeria and China.
6. Recent bank statement of account.
And prepare for a complete list of the documents you submits.