Abstract: Under heat-moisture treatment condition, potato starches were treated with different microwave radiation.The properties of the native and the treated starches were then studied by using SEM and brabender viscoamylograph.The results showed that the surfaces of the potato starches treated by microwave radiation became porous with concavity;the contents of resistant starch and amylase, pasting temperature, pasting stability and retro gradation increased;while the swelling power, solubility and viscosity decreased.