Abstract: [Objective]Calmodulin(CaM) was isolated and purified from bovine brain and identified with biochemistry, while CaM-couple antigen was prepared with EDC method.[Method]Calmodulin was isolated and purified from bovine brain by phenyl-Sepharose hydrophobic chromatography column.Its activity was detected by PDE method, the molecular weight was tested by SDS-PAGE, PAGE and electrophoresis behavior was observed, at the same time, its ultraviolet scanning spectrum were detected.Then CaM-couple antigens, prepared with cross linking agent-EDC, were used for animal immunization, and finally evaluated animal serum immunopotency by indirect Elisa.[Result]Cyclic nucleotide phosphodiesterase (PDE) can be activated by CaM, the results of electrophoresis showed to be homogeneous, and molecular weight was 17.3 KDa. The transport ratio of CaM-Ca~(2+) was faster than CaM-EGTA in SDS-PAGE, while the result was opposite in PAGE. The results of ultraviolet absorption-spectra showed there were 5 absorption peak at about 251 nm,260 nm,267 nm,272 nm and 283 nm. Then, animal serum can be purified by phenyl-Sepharose hydrophobic chromatography column and CaM-couple antigen is prepared by EDC method.