Abstract:63 mg calmodulin was extracted and purified from l kg acetone powder of malze germ germinated for 24 h, which is the highest record for the quantity of calmoulin purified from l kg plant materials. Our results showed that the calmodulin from maize germ had higher biological ac- tivity, could activate cAMP phosphodiesterase within a good range, and its UV absorption spec-trum, electrophoretic mobility on SDS PAGE in the presence or absence of Ca2+ and amino acid composition was similar to those calmodulins from other plant materials. The above-mentioned results indicated that maize germ is a suitable material for the extraction and purification of plant calmodulin.