Indium tin oxide(ITO) film was deposited by radio frequency(RF) reactive magnetron sputtering method.The characteristics of ITO film were studied by changing depositing ambience and the rapid thermal annealing(RTA) temperature.The transmittance,surface morphology,and roughness are analyzed by optical transmission spectrum,fourprobe method,AFM and XRD.The electroluminescent properties of devices weas discussed when the film of ITO was deposited under different conditions.It was also found that after the ITO was annealed,the luminescent intensity was obviously enhaned,the attenuation velocity was lowered and the electroluminescent peak changed.Through further analysis,it was concluded that different surfaces of ITO films might lead to the change of work function and the distributing of electric field in the device,as a result,the electroluminescent properties of the device was changed too.