interrelationship among the characters of the top and the root within a plant was investigated by deviding the roots of the plant into two parts and growing each one in two different environmental conditions, The roots grown on the poor environmental conditions such as over flooding moisture and overdried were less in numbers of root. shorter in root length. and lighter in root weight than those of good growing conditions, It was demonstrated that the roots grown under the poor environmental conditions affected not only the growing of the associated tillers but also the growing of all the tillers within a plant. In comparision with untreated plants. the culm length of treated plants was shortened. and the heading time of them was delayed. The most remarkable yield reduction was appeared at the over flooding moisture treatment. and the next was at the overdried treatment. The ten dency of yield reduction was more severe in sandy soil than that of clay loam.