The success of the mutant plants formation, dependent on the dose of irradiation used. Induced of mutan plants is influenced by several factors among others, the type of plant, time of irradiation phase of plant growth, the size of the plant material, and the thickness of the material to be irradiated. Dose gamma irradiation induces plant diversity Dioscorea rotundata effective is 10-30 Gy (Nwachukwu et al., 2009). This study aims to determine the lethal dose of gamma rays that may cause yam can grow 50 percent (LD50) in MV1 generation, and also wanted to know the effect of gamma ray irradiation dose on variability of growth patterns, leaf shape, form of tubers, long time grows after planting, stem diameter, number of tuber, tuber weight, length of tuber, and evaluated of the MV2 and MV3 generation