This study was carried out to investigate the genetic segregations and characteristics of off-type rice plants collected in Korea which were classified into seven groups based on grain characteristics. In the analysis of esterase electrophoresis, the long-grain red group was classified as 1 and 3 esterase isozyme zymogram(EIZ), the long-grain normal group was classified as 1, 3 and 7 EIZ. The extremely late sterility group was segregated variously as 1, 2, 1+2, 5, 6, 5+6, 7,8 ,7+8 and 12 EIZ. The long-grain red rice lines with 1 EIZ had a longer culm length and a lower length/width ratio to brown rice than the long-grain red rice lines with 3 EIZ. The long-grain normal rice lines with 3 EIZ had a longer culm length, shorter panicle length, greater number of tillers, lower length/width ratio of brown rice, and fewer number of grains per panicle than did the long-grain red rice lines with 1 or 7 EIZ.