In order to reveal the influences of crosslinking and acetylation modification on the properties of starches,the paste properties of crosslinked and/or acetylated sweet potato starch were investigated,and the morphological and structural changes of the modified starches were observed and analyzed by means of SEM,FT-IR and XRD.The results indicate that（1） after the crosslinking,the hot paste stability of the paste improves but the transparency decreases,and the freeze-thaw stability shows no obvious improvement;（2） the acetylated starch is of lower gelatinization temperature,better paste transparency and freeze-thaw stability,and poor hot paste stability;and（3） the dual modification by crosslinking and acetylation decreases the gelatinization temperature of sweet potato starch,improves the hot paste stability,paste transparency and freeze-thaw stability.