The purpose of the present study was to produce and characterize a monoclonal antibody against human beta 2-adrenergic receptor. Male BALB/c mice were immunized with glutathione S-transferase (GST) fusion protein of the C-terminal portion of the human beta 2-adrenergic receptor which was expressed in E.Coli. The immunized splenocytes were fused with myeloma SP2/0-Ag14 cells and the resulting monoclonal antibody was named as mAb beta C02. The monoclonal antibody beta C02 was determined as IgM subtype and then purified by anti-mouse IgM-agarose affinity chromatography. The results of ELISA, Western blot, and immunocytochemistry showed that mAb beta C02 recognized human beta 2-adrenergic receptor in the beta 2-adrenergic receptor-GST fusion protein and human epidermoid carcinoma cell line A431 with highly specific immunoreactivity. In addition, mAb beta C02 showed cross-species reactivity against beta-adrenergic receptor of hamster lung and rat brain as revealed by Western blot and immunohistochemistry. The monoclonal antibody beta C02 may provide useful tools for the study of the beta-adrenergic receptor of human and other species including rats.