【Objective】The present experiment was conducted to study the changes in nutrient concentration and microstructure of pumpkin crisps after microwave puffing. 【Method】Response surface methodology was used to optimize the technical parameters of pumpkin crisp processing. The pumpkin crisps made by using optimized protocol were analyzed for changes in nutrients， and microstructure of puffed pumpkin crisp was determined. 【Result】Changes in nutrient concentration have been observed in microwave puffed pumpkin crisps. the reducing sugar content increased by 3.36%， while the protein， starch， crude fiber， fat， and organic acid content decreased by 0.13， 3.50， 3.61， 0.17， and 0.04%， respectively. The results of SDS-PAGE and scanning electronic microscope showed that the weight of protein in pumpkin crisp decreased after microwave puffing， while the surface area crisps increased. 【Conclustion】The results revealed beneficial effects of microwave puffing in balancing the nutrients in pumpkin crisps from the health point of view. The microwave puffing was also found useful to enhance the quality and flavor of pumpkin crisp.