Ag nanoparticles were successfully grown on the surface of ITO electrode using an electrochemical method. By optimizing the growth conditions, Ag nanoparticles with the localized surface Plasmon resonance (LSPR) absorption peaks in the blue light region were selected. A series of blue OLED (organic light-emitting diodes) devices were fabricated using the selected Ag nanoparticle-loaded ITO electrodes, of which the luminous efficiency was improved compared to the reference devices. The LSPR effect of the Ag nanoparticles was utilized to increase the luminous efficiency up to 7.13 cd/A which was 24.8% higher than the reference device at the current density of 20 mA/cm2, and along with the peak of the emitting spectrum was blue shifted 5 nanometers. The results shown that the feasibility and the effectiveness of the Ag nanoparticles prepared by the electrochemically method in the OLED device.