B. Sadeghi - Department of Chemistry, Faculty of Science, Islamic Azad University, Tonekabon Branch, Tonekabon, Iran.
M. Jamali - Biology Student, Member of Young Research Club, Islamic Azad University of Tonekabon, Iran.
Sh. Kia - Chemistry Student, Member of Young Research Club, Islamic Azad University of Tonekabon, Iran.
A. Amini nia - Chemistry Student, Member of Young Research Club, Islamic Azad University of Tonekabon, Iran.
S. Ghafari - Chemistry Student, Member of Young Research Club, Islamic Azad University of Tonekabon, Iran.

We consider of the antimicrobial activity on the Ag nanoparticles(Ag NPs) aqueous solutions, which was prepared using a stabilizer, such as poly(N vinyl ۲ pyrrolidone PVP , for Staphylococcus aureus) S aureus and Escherichia coli E coli by measuring the minimum inhibitory concentration MIC . Antimicrobial effect of Ag NPs for S aureus and E coli was investigated using disk diffusion method Also, the Ag NPs did show the antimicrobial activity for the test organisms Antibacterial activity of Ag NPs was found to be dependent on the shape of bacteries.

Silver nanoparticles, Minimum inhibitory concentration, Colony Forming Unit (CFU)