Picea mongolica,Picea crassifolia,Picea pungens and Picea meyeri are the four spruce species growing in Minqin Desert Botanical Garden (38°35'N,102°58'E;1378 m asl).In combination with the analysis of photosynthetic pigments in needles and annual growth of main braches,the chlorophyll fluorescence imaging of needles were performed with prepared protocols using CF imager to determine the PSⅡ photochemical efficiency and non-photochemical energy dissipation,and their adaptability to steady-state light intensity.The results showed that,in the same habitat and management,the four spruce species seedlings aged 15 years exhibited similar good growth behavior and all adapted to desert climatic environment;the total chlorophyll contents were fairly higher in P.pungens while specific ratio of chlorophyll a to b (Chl a/b) was comparatively lower in P.crassifolia.Among the four species their photosynthetic response curves of PSⅡ photochemical efficiency were similar,but P.pungens illustrated an obviously different photosynthetic response in PSⅡ non-photochemical quenching coefficient (NPQ) from the other three.The consistent trend of NPQ irradiated with 150 μmol m^-2 s^-1 low actinic light for 10 min and PSⅡ photochemical maximum quantum efficiency (F_v/F_m) adapted for 20 min in dark exhibited the intrinsic photosynthetic characteristics of the species.That nearly no dissimilarities among the four species in NPQ irradiated with 1 500 μmol m^-2 s^-1 high actinic light and in PSⅡ maximum efficiency (F_v'/F_m') done with low actinic light demonstrated their physiological expressions of convergent adaptation.Comprehensive comparative analysis indicates that P.pungens and P.meyeri have lower ability in PSⅡ non-photochemical quenching in low light intensity,but a relatively higher PSⅡ operating efficiency (F_q'/F_m') in high light intensity,thus a greater ability for light-acclimation;while P.mongolica and P.crassifolia share almost unanimously PSⅡ photochemical and non-photochemical characteristics,and similar shade tolerance and light-demanding;the complete presentation of PSⅡ photosynthetic physiological characteristics in the four species indicates their convergent adaptability to Minqin arid desert climate,so they are feasibly important tree species in the northern shelter forestry construction in China and in the urban greening in dry areas.