We manufactured the inkjet printing system for the application into the nano Ag finger line interconnection process in Si solar cells. The home-made inkjet printer consists of motion part for XY motion stage with optical table, head part, power and control part in the rack box with pump, and ink supply part for the connection of pump-tube-sub ink tanknozzle. The ink jet printing system has been used to conduct the interconnection process of finger lines on Si solar cell. The nano ink includes the 50 nm-diameter. Ag nano particles and the viscosity is 14.4 cP at $22^{circ}C$. After processing of inkjet printing on the finger lines of Si solar cell, the nano particles were measured by scanning electron microscope. After the heat treatment at $850^{circ}C$, the finger lines showed the smooth surface morphology without micropores.