Abstract:The structures of the woods of the female and male trees in Bischoffia javanica, Flacourtia rukam and Nephelium lappaceum were comparatively described in detail.The results showed that the overall characters of the dioecious woods were generally quite similar, however, some significantly or extremely signicandy different charateristics, although being similarly occurred among the three species, still existed between the male and fe-male woods within the same species. Within the three species, the ratios of the wood fiber wall thicknesses /lu-men diameters in the female woods are larger than the ones in the male woods, and the number of the septate fibers and the fiber tracheids are smaller. It is considered that the female wood might possess a greater mechani-cal weight-bearing force in supporting the fruit.