The interface between the organic layer and the metallic layer of an organic light-emitting diode (OLED) is crucial to the stability and performance of the device. A uniform thin silicon nitride film, used as an anode modification layer, has been deposited on ITO coated glass by plasma enhanced chemical vapor deposition used as an anode modification layer. This thin film improves the interface of the electrode and the organic layer, prevents the diffusion of the metallic ions from the ITO anode to the organic layer and restrains the surface noisy leakage current. The device performance has thus been improved. The maximum electroluminescence (EL) efficiency of the device with the silicon nitride film is of several times higher than that of the device without it.