Abstract: The effects of shading on the activity of antioxidant enzymes, chlorophyll content, photosynthetic physiology and chlorophyll fluorescence of Saxifrage stolonifera were study to provide a theoretical basis for large-scale cultivation of S.stolonifera. The results showed that, the contents of chlorophyll were enhanced, activity of antioxidant enzymes was the highest, light saturation point (LSP), maximum net photosynthetic rate (A_max) and the average diurnal variation was the highest without “siesta”, quantum yield of PSII (Φ_PSⅡ), intrinsic photochemical efficiency of PSⅡ(F_v/F_m) and photochemical quenching coefficient (qP) were enhanced, non-photochemical quenching (qN) was minimum in 50% light transmittance condition. This indicates the optimum light condition of S.stolonifera in the region of Huaihua is the transmittance of about 50%.

Key words: Saxifrage stolonifera Curt., shading, photosynthetic characteristics