Abstract: After degumming and modifying the kenaf bast fiber,galacturonic monohydrate was applied to detect the remnants of kenaf roving's pectin and lignin after the bio-scouring,and the removing rate of pectin was also determined quantitatively. Influencing factors such as concentration,temperature,pH value and action time that have the effect on the remnants of pectin and lignin were analyzed. The experiments indicate the compound enzyme act on the pectin and lignin of kenaf roving and fiber quality is obviously improved to be compared with other methods.