Abstract: Abstract: Heat tolerance of 14 Ginkgo cultivars from the main planting section in China was investigated using physiological and biochemical measurements as well as the statistical analyses with spss softwave. Results indicated that heat tolerance of different Ginkgo cultivars could be distinguished effectively under a heat stress of 45 ℃for one week and could be effectively evaluated using a main component analysis and a cluster analysis from a data of the physiological and biochemical measurements. Cultivars of Su-nong、Tancheng300 and Xincun16 had the worst heat tolerance, while cultivars of Dong-tinghuang1、Tancheng2 and Da-longyan had the best heat tolerance. Heat tolerance of Ginkgo cultivars had little correlation with Ginkgo nucleus types.

Key words: Key words: heat stress, Ginkgo biloba, physiology and biochemistry, heat tolerance