Abstract: Effects of zinc on carbon metabolism and its enzymes activities in leaves of balsam pear were studied by field tria1．The results show that in the control plants stressed under a low level of zinc，there appear lower contents of sucrose，soluble sucrose，starch and zinc，lower activities of carbonic anhydrase(CA)and sucrose phosphate synthase(SPS)．However，the activities of amylase，acid invertase(AI)and neutral invertase(NI)in the upper and lower leaves are higher in CK than in other treatments．There is a significant correlation between the physiological properties．