ZnO NPs are metal oxide nanoparticles that offer novel biomedical uses ranging from diagnosis to treatment. UV-VIS utilized to analyze nanoparticles derived from Trifolium pratense flower extracts to be able gain knowledge concerning the optical features of produced ZnO nanoparticles. Aggregation of smaller nanoparticles confirmed via SEM images. FT-IR test verified ZnO NPs-bacterial cell wall polypeptide and glycogen binding. Nanoparticles' shape was determined using plant extract and confirmed using (XRD) analysis. antibacterial efficacy of ZnO NPs was obvious on all species of bacteria that studied, the most effective of it was on gram ve – than gram ve+.