Abstract: In order to clear the effect of different heating time on sweet potato cell tissue structure, biomicroscopy, scanning electron microscope and transmission electron microscope were used to observe changes of sweet potato cell morphology, intercellular spaces, intracellular starch granules and middle lamella at different stages of heat treatment (100℃, 0²1min) . Results showed that, with the extension of heating time, sweet potato cell morphology became more circular, the intercellular spaces became bigger, the intracellular starch granules first expanded and then ruptured, and the middle lamella became looser. Therefore, these above changes of sweet potato cell tissue structure during heat treatment would result in loose of sweet potato cell tissue structure, and it was advantageous to the complete separation of sweet potato cells, which would provide a theoretical basis for producing high cell-integrity sweet potato granules.