The last few decades have seen a flurry of activity in the synthesis and development of Plant growth promoting rhizobacteria and their derivatives as biocontrol agent. Various strategies can be envisaged to synthesize by exploiting the reactivity of this organisms with their derivatives by various researchers. Biocontrol agents and its derivatives were also reported to have promising bioactivities, including antibiotic production, antibacterial, siderophore and hormoes producing properties, primary and secondary metabolites producing activities. The aim of this book is to provide a brief knowledge about plant growth promoting rhizobacteria and their derivatives. We have included the PGPR and their characterization by various biometric parameters in soybean and mungbean. This study is carried out by Dr. Aarti Thakkar at Department of Microbiology and Biotechnology, Gujarat University, Ahmedabad (Gujarat). We hope the readers can enjoy this text and find it useful in their respective studies.