Mutation has been successfully employed in breeding of several food crop varieties. The aim of this study was undertaken to assess the effectiveness and efficiency of EMS and gamma rays in two varieties of soybean. Genetically pure, uniform and dry seeds were treated with different doses/ concentrations of gamma rays (10KR, 20KR, 30KR and 40KR) and EMS (0.1%, 0.2%0.3% and 0.4%). Mutagenic effectiveness and efficiency of gamma rays and EMS was calculated on the biological damage (lethality and seedling injury) in the M1
generation and both chlorophyll and morphological mutations observed in the M2
generation. The results indicated that, mutagenic effectiveness and efficiency decreased with increase in mutagenic treatments.