Both SRAP and EST-SSR markers were used to analysis genetic difference of 5 Populus deltoides varieties including P.deltoides.cv.‘Lux’(I-69/55) and 4 varieties related to it.(1)In SRAP analysis,21 primer pairs were screened and 287 bands were amplified,of which 209 bands were polymorphic.The percentage of polymorphic bands was 72.8% and the genetic similarity coefficients ranged from 0.548 1 to 0.769 2.(2)In EST-SSR analysis,17 primers were screened and 86 bands were amplified,among which 69 bands were polymorphic.The percentage of polymorphic bands was 80.2% and the genetic similarity coefficients ranged from 0.444 4 to 0.717 2.(3)The correlation of the genetic similarity matrix among the SRAP,EST-SSR and the combination data were different,of which the correlation between SRAP and the combination data (r=0.844 2),EST-SSR and the combination data (r=0.830 8) were significantly correlated.(4)Cluster analysis showed that there was difference between the genetic similarity assessed by SRAP and EST-SSR markers,but the results of SRAP and the combination data were consistent,which showed that SRAP markers were more effective in genetic difference analysis of close Populus lines.