The variation patterns of wood density of plantation poplar trees in 3 clones grown in 3 different beaches (Anhui Province,Hubei Province and Hunan Province) were studied.The results indicated that density variation in different Changjiang beaches is not significant, but significant in 3 different clones and 3 different tree heights. The radial variation pattern of wood density of 3 clones decreases from pith outward. The axial variation of density increases gradually from base upward,and decreases less after its maximum peak.