This study investigated the silver nanoparticles synthesis by biological method using Bacillus licheniformis extracts was successfully applied for the determination of quantitative biodegradation of malathion pesticide, which found in diverse water samples. Structural and morphological analysis of silver bio nanoparticles studied following Zeta potential, AFM, FTIR and HPLC analysis. The silver bio nanoparticles were stable in zeta potential which recorded of-32.22mV. The size and diameter of the nanoparticles were evaluated in average 144nm as displayed via Atomic Force Microscope. The Transform Infrared Spectroscopy (FTIR) was conducted to determine the various functional groups in the silver bio nanoparticles. The biodegradation of malathion by using silver bio nanoparticles was determined quantitatively using HPLC techniques, which began during seven days. We consider that this strategy has technological potential in the biodegradation of malathion pesticide contaminated water through green biosynthesis.