Abstract:To study the effects of different light intensities (10% light, 40% light, 70% light and full light) on light utilization characteristics for oiltea, we used 2year old seedlings of oiltea cultivar ‘Changlin No. 4’ as pot experimental materials, which were performed in an artificial climate incubator. The results showed that: (1) the net photosynthetic rate (An), electron transfer efficiency (ETR), light compensation point (Ic), CO2 compensation point (Γ), saturated light intensity (Isat), saturated CO2 concentration (Cisat), light respiration rate (Rp), dark respiration rate (Rd), light use efficiencies at leaf and plant levels were improved as light intensity increasing. (2) Under weak light condition, the photochemical efficiency of photosystem Ⅱ (Fv/Fm, ΦPSⅡ) was improved as the photochemical quenching coefficient (qP) increased, while the nonphotochemical quenching coefficient (NPQ) decreased, and the absorbed light energy was more allocated to the photochemical dissipation and excess excitation energy. (3) The ability of light absorption was enhanced by increasing chlorophyll content, lightharvesting pigment molecule numbers (N0), and intrinsic absorption crosssection (σik). However, the effective light absorption cross section (σik′) was increased, the minimum average life time at the lowest excited state (τmin) was extended, and the lightharvesting pigment molecules at the lowest excited state (Nk) was increased as light intensity reducing. It can be concluded that the electron transfer between lightcapturing pigment molecules and the generation of photosynthetic electron flow were limited, and thus oiltea leaves were failure to coordinate the improvement of light energy capture and electron transfer efficiency under low light environment, which declined the ability of photosynthetic carbon assimilation and the light use efficiency.