The aim of this study was the synthesis of silver nanoparticles in the aqueous leaf extracts of Cucumis sativa and investigate its antibacterial activity.Nanoparticles are being used in many commercial applications.It was found that aqueous silver ions can be reduced by aqueous extracts of plant parts to generate extremely stable silver nanoparticles in water. The results recorded from UV- spectrum, scanning electron microscopy are support the biosynthesis and characterization of silver nanoparticles.