Giant panda brain CaM was purified by Phenyl-Sepharose CL-4B hydrophobic chromatography and FPLC. The results of SDS-PAGE, PAGE and IEF indicate that the protein has been purified. The molecular weight and PI of CaM are 19 ku and 3.8, respectively. Giant panda brain CaM shows calcium ion effect in SDS-PAGE and PAGE. It can activate bovine heart PDE. The result of amino acid composition of giant panda brain CaM is similar to CaMs from other sources.