Taking one-year-old seedling of cultivar ‘Zhongcha 108’ of Camellia sinensis （Linn.） Kuntze as research object， variations of some physiological indexes of leaves under high temperature condition for 0， 4， 8， 24 and 48 h after spraying GABA were assayed. The results show that compared with seedlings without GABA treatment， the contents of GABA， free proline and chlorophyll in leaves of seedlings sprayed with 5 mmol·L-1 GABA increase to different degrees under high temperature condition， malondialdehyde content， relative electrical conductivity and soluble sugar content decrease to different degrees， and antioxidant enzyme （SOD， POD and APX） activities increase at different times in general. It is suggested that spraying GABA can relief high temperature stress on physiological damages of C. sinensis leaves to some extent and enhance heat tolerance of C. sinensis.