hello im interested in buisness visa type, what do i need? is it possible without invitation letter

You need to provide your passport and its copy, the filled-out application form with a recently-taken passport-style photo glued, and an invitation letter from your trade partner in PRC or issued by a trade fair. As far as I know, the invitation letter is necessary. If you cannot get it on your own, you can find an agency to get it for you.