Effects of wood species, wood moisture contents, and soldier proportions on the decomposition rates of Reticulitermes flaviceps (Oshima) and Nasutitermes parvonasutus (Shiraki) were studied. Decomposition ability of wood by R. flaviceps was greater than that by N. parvonasutus. Both termites consumed a greater mass of softer wood species than harder ones. The decomposition rate of wood by R. flaviceps was not influenced by the water content in wood; however, N. parvonasutus decomposed more wood mass with a 50±5% water content. Soldier proportions in a termite colony affected the mortality of termites and the decomposition rate of the wood.