Fabrication of paste at low temperature has been developed in order to apply for various electronic devices, such as bus electrode and address electrode in PDP, especially for enlargement of a screen size. In this study, nano-sized silver particles with 10 - 30 nm were synthesized from silver nitrate (AgNO3) by a chemical reduction method. To prepare Pb-free silver paste, the silver nanoparticles were mixed with conventional silver powder with an average particle size of 1.6 and conventional Pb-free frit. Thick films were fabricated from silver paste by a screen printing on alumina substrate and the films were fried at temperatures ranging from 550 °C to 600 °C. Microstructures of the fried thick films were analyzed by FE-SEM. Sheet resistivity of fried thick films was measured and also the relationship between sinterability and conductivity of these films were investigated.