i am living in Nigeria but want to visit HK for business trip

Hi, Sam! You can either apply from the Chinese embassy in Nigeria or from HK Immigration. First of all, prepare the following documents: application form (ID 1003A), your recent photograph, photocopy of the your passport, photocopy of your financial standing proof, e.g. bank statements, savings accounts passbooks, tax receipts, etc. and proof of employment (if any), e.g. company leave letter, salary slips, etc., photocopy of proof of transportation arrangement, and photocopy of proof of the proposed business visit to Hong Kong. Then submit the application. If you apply through the embassy, your application may be transferred to the HK Immigration as well.