The successive extractions of 70 tropical wood species from Southeast Asia and the Pacific regions were carried out using n-hexane, ethyl ether, acetone, and methanol as solvents. On the basis of the data, the relationships between the amount of extractives and each of decay resistance, resin spots on pulp sheets, and paint curing time were studied. Woods which contained more than 6 percent extractives showed a high resistance to decay by fungi and a very large number of resin spots on pulp sheets. Woods that contained less than 4 percent extractives showed no decay resistance and tended to be severely attacked. In the range of 4 to 6 percent extractives, the susceptibility to decay was medium. Generally speaking, when there were less than 6 percent extractives, the number of resin spots was small or nil. Curing times were not related to the amount of acetone extractives, but were related to n-hexane-soluble extractives.