Abstract: A UV curable conductive ink containing silver （Ag） nanoparticles was developed so as to satisfy the requirement of the ultra-fine PCB manufacturing presently, and the effects of Ag nanoparticles on dual-curing process and electrical conductivity were studied. The ink was prepared by uniformly dispersed Ag nanopartilces in organic solvent mixing with UV curable polymer, photoinitiator and thermal initiator. The curing process of the ink included UV curing and thermal curing and therefore it was a dual-curing process. Both Ag nanoparticles content and heat treatment conditions affected electrical resistivity. Electrical resistivity of the ink decreased to as low as 5×10^-6Ω·cm by using 70% silver nanoparticles and heat treat at 200 oC for 5 min.