In order to investigate the temperature on the quality of sweet potato powder by hot air drying, the color, rehydration capacity, particle size, viscosity, bulk density, reducing sugar and amylum of the sweet potato powder were compared. Results showed that hot air drying temperature had a significantly influence on the rehydration, particle size, viscosity and amylum of sweet potato powder (P<0.05). With the drying temperature rising, the dry basis moisture content decreased faster, the drying time shortened and amylum content increased. The sweet potato powder particle size prepared at hot air drying in 80 ℃ was the minimum, and the rehydration was the highest with good color.