Many dynamic correlations exist between human activity and ecological systems. In the case of traditional slash and burn agriculture, many systematic techniques which work in harmony with ecological systems have accumulated during the long period of human history. To evaluate responsible methods of land use, the ecological basis of such knowledge and its implementation effects should be understood. From this viewpoint, the effects of burning on the germination of viable seeds were investigated at a slash and burn site in the temperate zone of Kyushu. Seeds responded to the burning in one of the following three ways. (1) Burning decreased seed germination of annual herbs of Compositae such as Erigeron sumatrensis, E. annuus and Crassocephalum crepidioides. Thus burning is useful for weed control. (2) Burning stimulated seed germination of woody species such as Rubus spp. and Rhus javanica. This contributes to decreasing the leaching of inorganic nutrients from soil and to the rapid recovery of vegetation during a fallow period. (3) Burning had no effect on seed germination of some perennial herbs such as Eupatorium chinense var. simplicifolium.