Abstract: 17 casuarina clones grown in two sites in Hainan, viz. Daodong Forest Farm and Wenchang Forest Institute, were assessed for tree height, diameter at breast height, individual volume, axis persistence, stem straightness and survival percentage.The result indicated that genetic variations of those 6 traits were significant differences (pp<0.001) not only in tree growth indexes at each site but also genotype and site interaction among 17 clones. Meanwhile, the repeatability varied from 0.35 (axis persistence) to 0.85 (height). The genetic correlation was analyzed as well, it was showed that the height, diameter at breast height, individual volume and survival percentage had highly significant correlation. In addition, the mean genetic gains in height, diameter at breast height, individual volume, axis persistence, stem straightness and the survival percentage were 6.5%, 4.8%, 10.9%, 3.7%, 1.5% and 8.1% respectively. Three superior clones were selected from the 17 clones.