Abstract: A monoclonal antibody specifically binding to human and monkey CD38 antigens or a derivative thereof includes: antigen complementarity-determining regions CDR1, CDR2 and CDR3 of an antibody light chain variable region having amino acid sequences as set forth in SEQ ID NO: 3, SEQ ID NO: 4 and SEQ ID NO: 5, respectively; and antigen complementarity-determining regions CDR1, CDR2 and CDR3 of an antibody heavy chain variable region having amino acid sequences as set forth in SEQ ID NO: 8, SEQ ID NO: 9 and SEQ ID NO: 10, respectively. The monoclonal antibody or derivative thereof can be used as a component of a pharmaceutical composition or prepared into a suitable pharmaceutical preparation, administered alone or combined with other therapeutic means such as chemotherapy drugs, for treating tumors with positive CD38 expression, such as human myeloma and human lymphoma.