Abstract: This work focused on the impact of different addition of maltodextrin ( 10%, 20%, 30%, 40%) on the physical and chemical properties of spray- dried purple sweet potato flour.The results indicated that the spraydried purple sweet potato flour with higher MD concentration had higher values in lightness, chromatic aberration, fluidity, the retention rate of anthocyanins, but lower values in nutrition constituents, water holding capacity and hygroscopicity.The results also showed that with the increase of adding amount of maltodextrin, flour yield significantly increased at first, when the adding amount of maltodextrin exceeded 30%, the increase of flour yield was not obvious.Therefore, taken the physical and chemical properties and flour yield together, the best adding amount of maltodextrin was 30%.