The technology of monoclonal antibodies (MABs) was originated from the ideas that how antibodies of the B cells bind to the specific antigens to protect the body against foreign invasion. Nowadays, MABs drugs have been approved for more than 30 targets, they have been considered as one of the first-line immunotherapies which specifically target certain cancers. Due to their exquisite target selectivity and less toxicity, MABs have become the new mainstay of pharmaceutical industry. This review summarizes the history of discovery, basic structure, and in vivo production of the MABs. Meanwhile, this review introduces the basic therapeutic applications, mechanism and working process of MABs, MABs and its targeted cancers, issues with current MABs technology and corresponding methods of improvements are also discussed. Overall, MABs do have broad prospect in the future since its effectiveness of treating cancers with poor prognosis and wide therapeutic applications.