Abstract:Ginkgoes are ancient dioecious plants. Present, only Ginkgo biloba L., is exist as a living fossil plant. Botanists had studied it from different aspects in the world,due to the unique characteristics of gingko. Plant (sex physiological ecology is still a knowledge gap in plant ecology. This article measured the photosynthetic traits of the adult male and female ginkgo which grown in the suitable environment condition. The result indicated that the male and female ginkgo had similar response to light. The light saturate points (LSP), light compensate point (LCP) and dark respiration rate (Rd) between male and female were also no significant differences, however the net photosynthesis rate (Pn) of female ginkgo is significantly higher than male. From the vision of evolution, through comparison with other gymnosperms and angiosperms, the photosynthetic capacity of ginkgo is not obviously lower than other plants. It gave us a clue that the photosynthetic capacity is not the direct reason which restrict the distribution of ginkgo in tertiary.