Abstract: Using Caragana korshinskii from Jiuzhoutai of the North Mountains in Lanzhou city, measurement and analysis were made of the contents of Malondia dehyde(MDA), Superoxide dismutase(SOD), Peroxidase(POD), Ascorbic acid(ASA) and Proline in leaves after high temperature stress treatments of 30℃,35℃,40℃ and 45℃ respectively. The results showed that the content of MDA increased consistently, which indicated that the peroxidation function of membrane lipid was enhanced at high temperatures. The activity of SOD and POD increased first and then decreased,and the contents of ASA and proline increased on the whole, which demonstrated that C. korshinskii could resist oxidation by enhancing the activity of SOD and POD to eliminate the free radicals at high temperatures, but with the increasing of temperature, the ability of antioxidation was limited. The ASA and proline played an important role in strengthening the ability of antioxidation of C. korshinskii.