Abstract: ObjectiveThis experiment was conducted to compare the photosynthetic characteristics of introduced poplar clones to provide a scientific basis for breeding and promoting excellent poplar clones in poplar planting areas.MethodLi-6400XT portable photosynthetic system was used to measure the photosynthetic parameters of seven one-year-old introduced poplar clone seedlings including D5-9,D5-9,D5-20,D5-26,171,174,177 and 197 in natural condi-tions in Yili,Xinjiang, and comparative analysis was carried out between them and four local polar varieties.ResultThe diurnal variations of net photosynthetic rate(Pn)for the seven introduced poplar clones all presented double-peak curves. There was obvious midday depression of photosynthesis, which occurred in D5-26 and 171 due to stomatal limitation, while the rest clones were not impacted by stomatal limitation and non-stomatal limitation. D5-9 and 174 were poplar clones of high water use efficiency(WUE)and high light use efficiency(LUE),D5-20 and 197 were of medium WUE and medium LUE,D5-26,171,and 177 were of high WUE and low LUE. Pn of different clones were affected by photosyn-thetically active radiation(PAR),stomatal conductance(Gs)and transpiration(Tr)to different extents.ConclusionPoplar clone D5-9 has high photosynthetic ability and advantages in leaf area and growth,making it more suitable for the ecologi-cal environment in Yili. Therefore, cultivation of D5-9 can be promoted in Yili and other poplar planting areas with similar ecological environment as Yili.