A bacterium which has phospholipase A, activity was isolated from soil. It is aerobic, motile, oxidase-negative and has flagella. The G + C content of the DNA was 58.1 mol%, The major isoprenoids of cell wall were Q-8 and MK-8. The main cellular fatty acids were saturated straight chain (n-16) and cyclic (17:Delta) fatty acids. Based on its morphological, physiological and chemotaxonomic characteristics, this organism was placed in the genus Serratia, Nutritional factors affecting enzyme production were explored, Xylose and ammonium sulfate were the best carbon and nitrogen sources, respectively, Ferrous ions exerted a considerable positive effect on enzyme production, The optimal pH and temperature for phospholipase A, production were 7.0 and 30 degrees C, respectively.