L-arginine functionalized silver nanoparticles in controllable size were prepared by one-pot in-situ reduction of silver nitrate with L-arginine as the reducing and stabilizing agent. The reaction temperatures, reaction time, the molar ratio of L-arginine/AgNO3 and feed order of raw materials have influence on the synthesis of silver nanoparticles. Ultraviolet-visible spectrophotometry, transmission electron microscopy and X-ray diffraction were used to investigate their effects on the mean diameter, size distribution and dispersibility of silver nanoparticles. The obtained silver nanoparticles with mean diameter of (10±2) nm were dispersed in water, and then made films by blade coating. The films sintered at 170℃ for 60min can get resistivity of 16μΩ.cm, and its adhesion can reach 5A, which indicate its good application in printed electronics.