The study was carried out to investigate the changes of pectin and cell wall degradation enzyme of purple sweet potato and yellow sweet potato during their storage for 100 days.The purpose of the research was to find the variation of sweet potato.The sweet potato with Sportak dipping treatment(1 000mg/L) were placed in storage solution under 7 ℃,using the sweet patato stored at ambient-temperature as control(ck),to detect the physical indicators periodically.The results showed that Sportak dipping treatment combined with storage at 7 ℃ effectively prevented the rapid decrease of content of protopectin and slowed down the increase of activity of polygalacturonase and cellulose.The Sportak dipping treatment combined with storage at 7 ℃ could keep higher content of protopectin and improve the storage quality of sweet potatoin in the actual production.