Termites are widely distributed over the world, and quite abundant especially in tropical ecosystems. They are well-known as the so-called ecosystem engineers enhancing the subsequent decomposition of dead plant material (i.e. mineralization of organic carbon), while at the same time their own contribution to carbon mineralization has been gradually clarified being well considerable in tropical ecosystems. Here, I show the quantitative role of termites in carbon mineralization of annual aboveground litterfall (AAL) in a tropical forest of Thailand and make a comparison of the role among tropical ecosystems in Asia and Africa. I focus on the resource competition among decomposers, such as termites and microorganisms, and on the flow of carbon derived from AAL into the soil, suggesting the factors affecting the importance of termites and the decomposition processes of AAL on and in the soil. Finally, I will discuss the effects of termites on hot spots of soil respiration, which have been recently reported in a tropical forest and could significantly affect the estimation of net carbon balance in the ecosystem.