Abstract: By means of changing leaf-fruit ratio, the effects of sink-source manipulation on soluble sugar, starch content and enzyme activities with 5-year-old Camellia oleifera were studied. The results showed that a significant increase in soluble sugar and starch content was found in no fruit group (T₁), but its related enzymes activities was significantly lower than those in other groups. The soluble sugar and starch content increased slightly with the improvement of remained leaf number and showed a positive correlation. Activities of sucrose synthase(SS), sucrose phosphate synthase(SPS) had a single-peak curve and reached a maximum at T₃, T₄ group respectively. Meanwhile, the invertase and starch phosphorylase increased gradually with the increasing of source and sink. The research showed that the carbohydrate content and its enzyme activities in C.oleifera leaves was affected remarkably when the sink-source relationship was changed. Whereas, the leaf-fruit ratio that could improve the single fruit weight, seed-producing percentage and fruit yield needed to be further studied.