The property of four tropical hardwoods were analyzed. xylans, extracted with 24% of potassium hydroxide and purified according to ethanol titration procedure, were examined for Pn, the uronic acid, methoxyl groups and acetyl groups content. Only mangrove, whose xylan content is similar to that of hardwoods in the temperature zone, had the ratio of units of xylose residue to the units of uronic acid residue as high as that of hardwoods in the temperature one. Content of methoxyl groups showed the same result as uronic acid residue content. Various hemicellulose including D-xylose residue were contained in xylans extracted by DMSO. Acetyl groups content was compressed of 5.4% of MDX and 6.8% of RDX. Xylans unextracted by DMSO had acetyl groups. Pn measured by the viscosity method was about 200 and similar to the hardwood xylans of temperature zone.DPn calculated by uronic acid residue was simolar to that of tropical zone.