Abstract: In order to evaluate the influence mechanism of a wind and sand weather process on photosynthetic characteristics of cotton and its harm process in Xinjiang oasis, a field experiment was carried out on the variety of‘Xinluzhong 21’in the national field scientific observation station for desert and grassland ecosystem, three treatments were conducted including guaze covering (guaze), natural condition (CK) and washing without guaze (washing), the effect of sand amount on unit area cotton leaf on net photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate was analyzed after a wind and sand weather process. The results showed that the net photosynthetic rate of different treatments decreased significantly after wind and sand weather, and reached the minimum at the 18th day after injury, then kept at a stable level, the three treatments showed the same variation trend, but the net photosynthetic rate of per leaf showed the order of guaze ＞washing ＞CK, the net photosynthetic rate was significantly and positively correlated with stomatal conductance and transpiration rate, and significantly and negatively correlated with intercellular CO2 concentration; the sand amount on leaves decreased with the increase of time, and the change rate was high in the earlier stage and then reached a stable level, but the change of different components was different.