Abstract: Artificial hybridization was carried out by the method of accelerating floral cuttings to root by warming the flowerpots with Populus × Liaoningensis, P.pseudo-simonii, P.cathayana, P.suaveolens. The growth rhythm, super parent advantage and phenophase of hybrid clones at seedling stage were compared and analyzed. Result showed that 10 115 seeds and 6 676 seedlings were obtained, which emergence rate was 66%. The growth rules of tree height and ground diameter accord with "S" curve. There was a significant difference in growth of the clones. The growth of LX-6 was the largest in all 2-year-old clones, with the heterobeltiosis of tree height and DBH were 22.06% and 42.93%, which were higher 35.18% and 48.17% than CK, The LD-3 takes the second place. A larger variation coefficient among different individuals in the clone was up to 32.27%. The phenological period of each clone was 38 days in the maximum cap period and 5 days in the prosperous stage of the leaf; the longest in the CL-2 growth period was 204 days, and the shortest in the TL-13 was 179 days. The influencing factors of the growth period of each clone were mainly the differences in the late phenophase.