Objective To evaluate the clinical value of serum MUC1(sMUC1)in the patients with multiple myeloma.Methods The enzyme linked immunosorbent assay(ELISA)was used to compare the sMUC1 levels in the 12 cases of newly diagnosed multiple myeloma.15 cases of post-chemotherapy and 46 healthy donors.Results The mean concentration of sMUC1 in the newly diagnosed patients with multiple myeloma was 33.44 U/ml(10.86～88.80 U/ml).In the patients of post-chemotherapy the mean concentration was 11.6U/ml(3.92～22.22 U/ml),and in the healthy donors the concentration was 12.81 U/ml(3.84～30.45 U/ml).The level of sMUC1 in the new diagnosed patients was significandy higher than that in the patients of post-chemotherapy(P=0.001)and healthy donors(P=0.000).There was no significant difference between post-chemotherapy and healthy donors(P=0.461).Conclusion sMUC1 may be one of the tumor markers for the diagnosis of multiple myeloma.sMUC1 could also be used as one of the indicators of prognosis and the evaluation of the chemotherapy efficacy.sMUC1 might be a potential target for the immunotherapy to the patients with multiple myeloma.