The high temperature(HT)stress caused by global climate change has seriously affected the growth and development of soybean.In recent years,HT became one of the important factors leading to the decline of soybean yield and quality in Huanghuaihai.This study attended to identify the HT resistance germplasm resources and establish a scientific method for evaluating the HT tolerance.By taking use of 35 soybean varieties that were collected from the Huanghuaihai ecological and the Chinese soybean micro-core germplasm resources, we determined the phenotypic variation at flowering stage via the field artificial warming(44.11.47 ℃).Based on the comprehensive physiological and biochemical traits related to the HT stress,we constructed a set of HT resistance evaluation standards for soybean with pollen vigor(pollen germination rate)as the main indicator, and used this standard to screen for HT soybean germplasm resources.The results found that compared with the natural environment in the field,the pollen germination rate,the number of pods per plant and the number of effective branches after HT stress showed a significant decrease,while the relative conductivity increased significantly.According to the HT resistance coefficient significant responding to HT stress traits,the principal component and membership function were standardized and analyzed and estimated the comprehensive evaluation value(C)of soybean response to HT stress and clustered analysis based on C value.Finally,the HT resistance of soybean varieties classified into 5 types(I,sensitive type;II,strong sensitive;III,medium;IV,tolerance;V, strong tolerance).The grading standard is basically consistent with the field phenotype identification,indicating that the method can be used for the screening and identification of soybean HT resistance germplasm resources, and two HT resistant soybean varieties(Jidou 21 and Nannong 34)are initially screened for further research, which laid method and material basis on breeding for HT resistant new varieties and HT resistance molecular mechanism.