Abstract: Eleven TaLEA overexpressed Populus simonii×P. nigra transgenic lines and wild-type control were studied for growth traits and leaf anatomy. The results showed that in regards to leaf area, stomatal density and leaf thickness, the XL11 lines were significantly lower than the other lines tested. On the contrary, XL11 lines epidermis, palisade and spongy tissue ratios and pore size were significantly higher than in the other lines. XL11 lines for the material,the TAIL-PCR method using cloned sequences flanking the insertion site and found AP2/PthRAV (XM_0023114021). Quantitative analysis of relative expression of the AP2/PthRAV lines in dwf1 was significantly higher than other transgenic lines, at 7-78 times of the average. A preliminary view of dwf1 lines in the change of growth and anatomical structure of leaf traits may be related to the upregulation of AP2/PthRAV genes.