Abstract: The leaves of five genotypes(TC121,TC152,TC332,TC510 and TC970) in Populus tomentosa Carr.were used as explants to study the differences of in vitro regeneration competences among genotypes.Single factor and orthogonal experiment designs were used to establish and optimize the leaf regeneration system of P.tomentosa.The results showed that the regeneration competences were affected by genotypes,and there were obvious differences among genotypes in regeneration rates.The regeneration rate of TC152 reached 97.0% on the medium of MS + 6-BA 1.0 mg/L+ NAA 0.05 mg/L + sucrose 30 g/L + agar 6 g/L.The regeneration rate of TC970 was 94.7% on the medium of MS + 6-BA 0.5 mg/L + NAA 0.05 mg/L + sucrose 30 g/L + agar 6 g/L.After medium optimization,the regeneration rate of TC332 had been improved to 72.3%.However,the regeneration rates of TC510 and TC121 remained below 50.0%.