With global climate been warming, heat stress has become one of main factor s influenced crop product around the world. In cotton growing areas of china, especially in Yangtze River valley, unexpected periodic extreme high temperature usually occurred in the period of full florescence and boll setting, and this resulted in higher bud and boll abscission rates and lower lint yield. So screening of heat resistant cotton germplasm is extremely urgent subject. In this study, we planted 200 different thermotolerance cotton germplasms in Tulufan of Xin Jiang province located in west of china. We investigated the bud and boll abscission rate, pollen vitality, situation of leaf wilting, pollen morphology, infertility seed rates and so on. And then 29 germplasms with different hot tolerance were growed in Anyang, Henan. The pollen germination rate in vitro at 30℃、35℃、 40℃、 45℃ and 50℃ were investigated respectively. There were significant difference in field index and pollen germination rate among different thermotolerance cotton germplasms. Meanwhile there were different correlation in the ten identify index. Based on the pollen germination rate in vitro and the field index of hot tolerance, 29 germplasms were grouped into four types including heat tolerance, moderately heat tolerance, heat suseptible line and moderately susceptibl