We have investigated the structural and electrical properties of Si-Zn-Sn-O (SZTO) thin filmsdeposited by RF magnetron sputtering at various deposition temperatures from RT to 350℃. All theSZTO thin fims are amorphous structure. The mobility of SZTO thin film has been changed dependingon the deposition temperature. SZTO thin film transistor shows mobility of 8.715 ㎠/Vs at roomtemperature. We performed the electrical stress test by applying gate and drain voltage. SZTO thin filmtransistor shows good stability deposited at room temperature while showing poor stability deposited at350℃. As a result, the electrical performance and stability have been changed depending on depositiontemperature mainly because high deposition temperature loosened the amorphous structure generatingmore oxygen vacancies.