The last few decades have seen a flurry of activity in the synthesis and development of Plant growth promoting fungi 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, secondary and volatile metabolites producing activities. The aim of this book is to provide a brief knowledge about plant growth promoting fungi and their derivatives. We have included the their characterization of Trichoderma citrinoviride by various biometric parameters in soybean and mungbean.