This study was conducted with the aim of gaining the outcomes of polyploidy induction by soaking black sesame seeds, Sesamum indicum Linn, in 0.0%, 0.1%, 0.2%, 0.3% and 0.4% colchicine for 24 hours. When checking the characteristics of polyploidy using the fifteen days old seedlings’ abnormalities as indicators. The abnormal seedlings grew very slowly. The stems were short containing only cotyledon leaves and the first pair of unifoliate leaves. Their hypocotyls were swollen, fat and short while epicotyls did not extended but stunted. However, these hypocotyls could be extended or grew longer but they would take more time. The examination revealed that the sesame seedlings which were not treated by using colchicine could grow normally. In contrast, those, which were treated by using colchicine, yielded abnormal seedlings. The higher percentage of the concentrations of colchicine, the more abnormal seedlings were obtained as the following.
