Abstract: The sugar content and sugarmetabolizing enzymes activities in stems of Populus× euramericana ‘Nanlin895’ aseptic seedling under different concentration stress of NAA were investigated, and also the correlations were analyzed. The results showed as follows: (1)The sucrose and fructose content were increased in stems of Populus×euramericana ‘Nanlin895’ aseptic seedling. Meanwhile, acid invertase (AI) and neutral invertase (NI) activities were enhanced. Besides, sucrose phosphate synthase (SPS) and sucrose synthase (SS) activities were reduced under the 100 mg/L NAA treatment. On the contrary, the role of higher concentration of NAA, which was higher than 100mg/L, was negative. (2)Under NAA treatment, the sucrose and fructose content were significant positive correlation with the activity of AI. Also there was significant negative correlation between sucrose content and the activities of SS and SPS, but the fructose content was not correlative with the SPS and SS activities. The fitting concentration of NAA would be taken definite promotion role in the process of sugar metabolism in the stems of Populus×euramericana ‘Nanlin895’ aseptic seedling.