A pot experiment was conducted to study the effects of different water treatments[CK(with soil water content 85%~90% of field capacity),T₁(with soil water content 65%~70% of field capacity),T₂(with soil water content 50%~55% of field capacity),T₃(with soil water content 35%~40% of field capacity)] on the photosynthetic and physiological characteristics of Camellia petelotii seedlings.The results showed that:(1)All plants were dead in T₃ treatment,indicating that soil water content 50%~55% of field capacity is the threshold to water stress.(2)When increasing drought stress,the net photosynthetic rate(P_n),stomata conductance(G_s),transpiration rate(T_r),stomatal limitation values(L_s) and actual photosynthetic efficiency of PSⅡ(Φ_PSⅡ) all significantly decreased,while the intercellular CO₂ concentration(C_i) and water use efficiency(WUE) kept invariable.The decrease of P_n in drought stress of C.petelotii was mainly caused by non-stomatal inhibition.(3)Compared with CK,the minimal fluorescence(F₀),maximal fluorescence(F_m),maximum quantum yield of PSⅡ(F_v/F_m) and malondialdehyde(MDA) content of leaves in T₁ treatment did not change significantly,while in T₂ treatment,F_m and F_v/F_m decreased significantly,F₀ and MDA content enhanced significantly,which indicated that the reaction center of PSⅡ of C.petelotii was not injured in T₁ treatment,while the photosynthetic apparatus was destroyed irreversible in T₂ treatment.(4)The contents of total chlorophyll(Chl),chlorophyll a(Chl a),chlorophyll b(Chl b),carotenoid(Car) in leaves,Chl a/Chl b,Car/Chl,relative leaf water content(RWC) all decreased with increasing drought stress,while the proline(Pro) content increased under T₁ treatment and decreased under T₂ treatment.The results proved that C.petelotii was extremely sensitive to drought stress,the water deficit would restrain its photosynthesis.Intolerance to drought for C.petelotii may be an important reason to limit the spread of its population.