Abstract: For efficient planting of walnut, we took 11 varieties planted in Longnan area of Gansu as research subjects to study the differences of photosynthetic response. By using an automated light curve program in the LI- 6400 portable photosynthesis analysis system (LI- COR, Lincoln, Nebraska, USA), we analyzed the differences of light saturation point (LSP ), light compensation point (LCP ), net photosynthetic rate (Pn ), maximum net photosynthetic rate (A max), dark respiration rate (Rd ), intercellular CO2 concentration (Ci ), stomatal conductance (Gs ), transpiration rate (Tr ), apparent quantum yield (AQY ) and other parameters of the 11 varieties. The results showed that: the photosynthetic efficiency ranked as‘Vina’>‘Yuanfeng’>‘Shanhe No.5’>‘Chandler’>‘Wen 185’>‘Xiluo No.3’>‘Xiangling’>‘Qingxiang’>‘Qieke’>‘Xiluo No.2’>‘Jing 861’. Among the 11 varieties, the light intensity of‘Vina’adapted to a wide range and was suitable for close planting in both strong and low light ondition; ‘Yuanfeng’ and ‘Shanhe No.5’ were suitable for close planting under strong light condition;‘Chandler’had a strong adaptability and could be properly close planted under strong light condition; the planting space of‘Qieke’and‘Xiluo No.2’should be carefully maintained as their light intensity adaptability was narrow,‘Qieke’was suitable for planting in areas with strong sunlight while‘Xiluo No.2’was suitable for areas with weak light;‘Xiluo No.3’,‘Qingxiang’and‘Xiangling’had high weak light utilization efficiency and were more suitable for close planting under low light condition. Among the 11 varieties, the shade tolerance of‘Jing 861’is the best and suitable for close planting in the areas with weak light intensity.