Abstract: Based on the techniques of amplified fragment length polymorphism (AFLP) and microsatellite (SSR) marker, a hybrid molecular linkage map of Populus deltoides×P. cathayana was constructed. 19 major groups, 16 doublets, 7 triplets and 5 small groups were identified in this map.356 AFLP makers and 12 SSR markers, total 368 makers, were ordered on the 19 major groups. This map covered 3 382.4 cM of genome length, and the average distance between two markers was 9.69 cM. The estimated genome length was between 2 607 cM and 3 319 cM and was 3 042 cM in average. The expected genome coverage was calculated and it was 96.7% with the equation of Lander,and it was 98.4% with method of Bishop et al.