In this work, we fabricated organic thin-film transistors (OTFTs) by channel doping with silver nano-particles (Ag-NPs). Ag-NPs whose diameter of 5-10 nm were made with AgNO3 resolved into NaBR4 solution and then mixed with Poly-4-VinlyPhenol (PVP). OTFTs were fabricated on the double side polished glass substrate with Indium-Tin Oxide (ITO) of 150 nm thickness. ITO served as the gate electrode. Polymer based Ag-NPs as a channel doping layer were spin coated on Spin-On-Glass (SOG) dielectric layer. On the Ag-NPs layer, 600mm thickness of pentacene was deposited. The effect of Ag-NPs based OTFTs have been examined and these prototype organic transistors showed the excellent electrical characteristics with the field effect mobility of 0.71 cm2/Vs and Ion/Ioff > 104.