The properties of sweet potato starch adulterated with maize starch were analyzed by scanning electronic microscope,laser particle analyzer,rapid visco-analyzer,and X-ray diffractometer.The results showed that the content of maize starch in sweet potato starch was significantly correlated to average diameter,peak viscosity,and peak area at 5.6°.The maize starch content in sweet potato starch can be rapidly predicted according to the regression equation.