Abstract: This study tests the bacterial resistance of hemp fiber and analyzes its anti-bacterial mechanism through the morphological structure and chemical composition of the fiber.The results indicate that the anaerobic bacteria cant′ survive in the inside of hemp fiber where exist a large specific surface-area,lots of holes and voids,and much oxygen.Hemp fiber contains a lot of phenols and their derivatives which are effective natural bacteria resistant materials and can inhibit the metabolism and physiology of fungi and other microorganism,break the structure of germ,and repress the generation of fungi until the death of germ.Moreover,the existence of a small amount of cannabinol is adequate to kill the fungi microorganism.