Genetic variance of seedling biomass,growth characters,including height,DBH(diameter at breast height) and divaricate characters,in 8 poplar crosses were analyzed.The results indicated that the significant difference in height,diameter and divaricate characters existed among 8 different crosses and various clones.Heritability of height,DBH and divaricate were 77.75%,52.64%,56.96%,and the highest is height.The average of 8 poplar crosses in height and DBH excess T120 and I 69 4.7%, 5.3% and 5.6%,6.6%?I 69×S3244 and I 69×I 63 were best among 8 crosses , excessing I 69 9.4% ,9.9%和10.4%,11.4%.It is possible to select excellent clones from these crosses.