I will attend training at HongKong. what are the requirements to get visa

Is there a company in HK responsible for this training? If yes, the company can be your sponsor to help you to get the entry permit. You need to send a copy of your passport, an invitation letter from the company, a filled-out application attached with a half-length color photo, a copy of round-trip tickets, a financial standing proof, and maybe a cover letter of your company to the company in HK. Then ask the company to submit the application for you to the HK Immigration Department. If you don't have such a company as your sponsor, you can submit the application to the China embassy in Ethiopia or mail the documents to HK Immigration Department.