Cluster bean (Hindi: Guar) is an important crop, majority of which is grown for gum (galactomannan) purpose and the rest is used for culinary purpose, cattle feeding etc. Since, there is less variability in the crop and has small closed flower structure. It is difficult to improve the crop using selection and hybridization programme. Therefore, mutation breeding plays an important role in improvement of this crop. The book bring forward the fact that the frequency economic mutation is very less and mutation leads to different types of abnormalities in the plant. This book can help post graduate students in conducting mutation work/ experiment. The present investigation on cluster bean was under taken to find out the variability induced by different doses of gamma rays and different concentration of EMS. Out of 18 characters under study, Pusa Navbahar showed significant variability developed for 7 characters, whereas, GC 1 showed significant variability for 13 characters.