In order to determine the impacts of natamycin on postharvest asparagus, respiratory rate, color, shear force, weight loss, free polyamines, bacterial and mold count were examined under low temperature. The results indicate that the natamycin treatments reduce respiratory rates of asparagus, inhibite the increases of weight loss and putrescine content, and cut down the total molds of 1~3 orders of magnitude effectively. The peaks of spermine and spermidine appear earlier in natamycin treatments and their contents are increased. Moreover, the asparagus with natamycin has better appearance and texture.