In nanotechnology science several methods of chemic al synthesis of silver nanoparticles (AgNps) are kn own. These methods involve high pressure, temperature and ener gy.Development in the green synthesis of Ag Nps is an important step in the field of application in nanot echnology. Accordingly, researchersare developing g reen methods that are eco-friendly, cost-effective and energy-ef ficient. Herein we report a green approach for the synthesis of AgNps. Thec olloidal silver particles were synthesized by reduction of AgNO 3 with D (+) lactose as a reducing agent .The morphology and structure of synthesized Ag Nps were characterized usingRayleigh scattering, transmission electron microscopy (TEM), UV/Vis spec trophotometry, dynamic light scattering (DLS) and X -ray diffraction method (XRD). Also the Ag Nps in differ ent concentration and shapes wereanalyzed for their antimicrobial activity agansit 4 positive and negat ive bacteriausing agar disc diffusion methodand fun gusFusarium oxysporum cultivated on Potatoes Dextrose Agar medi um (PDA). Results indicated that synthesized Ag Nps are relatively same in size (15 to 40 nm) and almost sp herical.Also resultsshowed that the AgNps had inhib ition activity against testedmicrobials, especially on Staphylococ cus aureus (+), (C 27 :16 ± 0.55 mm)and Fusarium oxysporum (0 to 100%). The effects of concentration and size of the synthesized Ag NPs on antimicrobial activity we re also discussed.