This book is basically based on applied research whose main objectives were: 1.To isolate Plant Growth Promoting Rhizobacteria (PGPR) from mash bean rhizosphere. 2.To determine the effect of co-inoculation of Rhizobium sp. with PGPR on growth, nodulation and nitrogen fixation of mash bean. In the course of this research experiment, we concluded that nitrogen fixation and yield of mash bean was enhanced by the application of PGPR. Response of mash bean was more pronounced to the inoculation of PGPR along with chemical fertilizer as compared to application of chemical fertilizer alone and control.