BUSINESS VISIT TO CHINA, HOW TO DO

First you need to go the embassy to make an appointment on every Tue or Thursday from 15:00 to 17:00. At this time, you need to handle the related documens. For your situation, you need to prepare the passport, the application form with recent taken photo, invitation letter from partner in China, original invitation letter of duly authorized unit or confirmation letter of invitation issued by the Chinese government departments, companies and social organizations authorized by the Chinese Foreign Ministry, introduction letter from your company, your company's certificate, lastest 6 monthes bank statement.
Then you need to wait for an interview and you get one to two weeks after the interview. When picking, you need to pay the fee, 5000 naira for single entry, 7500 naira for double entries.