Atmospheric pressure microplasma interfaced with a AgNO3 aqueous solution was used to synthesize the colloidal Ag nanoparticles.The resonance peak of the UV-Vis absorption blue-shifted and became narrower as the solution temperature increased from 0 °C to 70 °C,and both peak position and bandwidth of UV-Vis absorbance initially increased as the current increasing from 1 mA to 12 mA and were both observed to decrease as the discharge current approached the 12 mA.