Heat tolerance was evaluated of for 196 grape accessions from National Grape Resources Repository at Zhengzhou Fruit Research Institute of CAAS were evaluated using the chlorophyll fluorescence parameter Fv/Fm. The results showed that the range of the Fv/Fm was from 0.0792- to 0.6836, displaying varieties differences among the varieties, with the distribution frequency distribution of all heat tolerance Fv/Fm accorded within normal distribution. It represents a and belonged to quantitative trait controlled by multiple genes. Based on sequential clustering method, the grade of grape heat tolerance could be divided into 3 level, which was weak, medium and strong, . and the The corresponding threshold value was were ≤0.3,（0.3, 0.5] and >0.5, respectively. Based on the above evaluation, Forty-eight48 heat-resistant grape accessions were screened out, germplasm including Shuangxixianzhi03, Meilingshan-ciputao1301, Lingyeputao0945 and Hetianlv were screened,. tThe heat tolerance level of Chinese wild grape species were was, in general, higher than that of others Vitis species / varieties. on the whole. The result in from this study would provide valuable insights for breeding heat tolerant grapes and for studying the mechanisms of grape heat resistance.