I'm nepalese. I've friend in China and he has got job for me how can I get Chinese visa?

Hi Bibek! So you want to apply for a work type (Z) entry permit? If so, you should firstly prepare the following documents:
1 Application Form with a recently-taken color photo glued to.
2 Valid passport and a copy of information page
3 Invitation letter issued by duly authorized Chinese institute.
4 Original and copy of one of Alien Employment License (work permit)
5 Original Diploma and a copy of it.
6 Original and copy of foreigner physical examination record.
7 Personal written statement (covering letter with details as follows: place to visit, name, address and contact number of the inviting / contact company or person).
8 Other documents required by the Embassy

Then go to the embassy to submit the documents.