Abstract: Desert steppe is a type of transition form of steppe and the buffer zone between desert and typical steppe where the population height is sensitive to natural and human factors. The present study assessed the seasonal effect of grazing intensity, one of the human factors, on population height of three constructive species in desert steppe, including Stipa breviflora, Artemisia frigida and Cleistogenes songorica. We found that during the period from June to September, population height of the three constructive species was reduced with the increase of grazing intensity. During the period from early June to September, the population height of Stipa breviflora was gradually reduced. For Artemisia frigida and Cleistogenes songorica, their population height was increased at first and then decreasedfrom May to September, and the maximum was observed in August.