Objective:To prepare monoclonal antibody (MAb)against monomeric C-reactive protein. Methods:BALB/c mice were immunized with mCRP-BSA and the spleen cells of the mice were fused with myeloma cells SP2/0 at the ratio of 5∶1. Monoclonal hybridomas were screened by competitive indirect enzyme-linked-immunoadsorbent assay (ELISA)and limited dilution. Mouse ascites were prepared by intraperitoneal injection of hybridoma cells. MAbs to mCRP was purified by Protein G Affinity chromatography methods. The specificity and activity of ascites antibody were determined by Western Blot and indirect ELISA. The protective effects of this antibody influenced on cardiomyocytes were further studied. Results:Strain of hybridoma cell line could secrete MAb stably. After purification,the obtained monoclonal antibody can decrease mCRP induced TGF--茁 expression on cardiomyocytes. Conclusion:The obtained strain of hybridoma cell line could secrete MAb stably,and purified MAb had protective effect on cardiomyocytes. [Key words] monomeric C-reactive protein;monoclonal antibody