Abstract:In June and July, net photosynthetic rate and its light intensity coefficient, as well as light saturation point, near saturation point and half saturation point are the highest during sevaral days after fully expanded leaf; namely, in uppermost expanded leaf for Aneurolepidium chinense. Aforesaid characteristic indexes of younger leaves and older leaves are lower. The difference of net photosynthetic rate or light intensity coefficient Of photosynthesis in ‘the leaves of various age with falling light intensify reduces gradually. Light compensation point in halfunfolded young leaf is lower, then increased gradually with the ageing leaf. The prime-leaves play the major role in photosynthetic production due to the strong capability of light utilization. The young leaves have the ability to utilize weak light and the old leaves are more tolerant to shade.