Abstract: The research and development of monoclonal antibodies (mAbs) is a rapidly developing field. From the first generation of murine mAbs to the fourth generation of fully human mAbs, the efficacy and safety of mAbs in the treatment of various diseases have been continuously improved. In order to regulate the development and evaluation of mAbs, drug regulatory agencies and pharmacopeias of America and China have tried to issue feasible test procedures and acceptance criteria for quality evaluation of mAbs and biosimilars. Mass spectrometry (MS) technique with high sensitivity, resolution, selectivity, and specificity has become an important tool to evaluate the quality characteristics of monoclonal antibody-related products or specify mAb quality. The research of MS-based monoclonal antibody study involves structure characterization, impurity analysis, pharmacokinetics/pharmacodynamics (PK/PD), etc. This review focuses on the current quality control requirements of mAb related products and the development of MS technique for mAb quality characterization and specification. It is expected to provide information and references for evaluating the quality of monoclonal antibodies under research and development.