The seed shattering played a key role in the crucial step of rice domestication. Because it has been important to increase the yield human had to select the rice varieties and species with low shattering degree. The shattering habit of rice is considered to be under the relatively simple genetic control compared with other characteristics related to domestication. Several recessive genes associated with the formation of an abscission layer, sh2, sh4 and sh-h on chromosomes 1, 3 and 7, have been reported. In addition, the grain shattering of rice is considered to be caused by seed abscission. The morphology of the abscission layer can differ in many different rice varieties that show varying degrees of shattering. Accordingly, it is important to elucidate the molecular mechanism to determine why some varieties do not have abscission layers and have an easy-shattering trait. In this study, analysis of QTL for grain shattering was performed to determine the location of QTLs on the whole chromosomes of rice. Also, we tried to construct a physical map for qPs6