Does embassy of China will issue us the visa or we need more other document?

You cannot apply it individually. You need to entrust an authorized Chinese travel agency and apply for a group tourist type by providing your passport and its copy, recent photos, cover letter from your company or office, original and photocopy of Invitation Letter issued by the travel agency, and itinerary and name list of the group. However, the presentation of those documents does not gurantee the issuance.