Abstract: Based on the results of 4-year-old (1983-1987) provenance test, with 21 seed sources introduced from Australia, at 5 sites both in Guangdong and Hainan provinces, this paper analyses the variation of height and D.B. H. growth among the seed sources of Acacia mangium. It showed that there are significant differences in the growth rate among these tested seed sources. The variation coefficient for height and D.B.H. are more than 0.30 and 0.40 respectively and the provenance variance has accounted for above 50 percent of the total phenotypic variance,illustrating a tendency of strong genetic control for both traits. There is a relative stability for each seed source to grow at sites with different soil conditions. The superior seed sources are distributed both in PNG (13459 and 13460) and in Claudie River (13229), as well as in the low altitude area to the south of 17.5°S in Queensland (13242 etc), Australia. It is expected to get a genetic gain with 8.54%, 9.18% and 16.81% for height, D.B.H., and volume respectively, comparing with the grand mean of provenance test stand, just through superior seed source selection.