Abstract: In order to reveal the adaptation strategy of Populus tomentosa to the environment,and to provide scientific basis for better forest management,the 10-,20-and 35-year-old Populus tomentosa in the Yellow River floodplain of western Shandong Province were taken as the research objects,and 10 indicators of branch and leaf functional traits were measured,and the changes of community functional traits with the different stand ages were analyzed,and the main indicators affecting the changes of functional traits were clarified,and the relationships between functional traits and environmental factors were analyzed respectively.The results showed that（1）the coefficient of variation of branch density was the smallest,10.431,and the coefficient of variation of leaf nitrogen-phosphorus ratio was 94.243,which indicated that leaf nitrogen-phosphorus ratio was greatly affected by the different stand ages,while branch density was more stable.leaf nitrogen-phosphorus ratios were significantly lower than 14 in three stand ages,indicated that the growth was manly limited by nitrogen.（2）As the age of the forest increased,the soil environment was improved,soil total nitrogen and soil available potassium showed an increasing trend,and the soil bulk density showed a decreasing trend,these changes were conducive to the better growth of P.tomentosa.（3）Among the environmental factors,stand density,soil available potassium content,soil bulk density and soil water content were the environmental factors that significantly affecting the growth of P.tomentosa.The results proved that the functional traits of the P.tomentosa showed strong adaptability in balancing growth and environmental changes at different stand ages,and that the growth of P.tomentosa in this region was mainly limited by nitrogen,so nitrogen fertilizer could be applied appropriately to facilitate its growth.