Low-voltage-driven thin film electroluminescent devices are developed by using lowxesistivity stacked film SiO2/Ta2O5 and Al2O3/Ta2O5. At 50 Hz sinusoidal wave voltage excitation, its threshold voltage is below 40 V, and brightness is above 200cd/ cm2 at 60 V. Its characteristics of brightness～voltage (B～V) curve and integrated charge～voltage (Q～V) figure are different from usual one. By using a model of space charge- limited- Cur rent, the distr ibution char acter istics of the space charge and electrical field acrosss the phosphor in the device are analyzed, the mechanism of low-voltage-driven thin film electroluminescence, and the characteristics of B～V curve and Q～V figure are well explained. It is considered that the electroconductivility of the stacked film is the key of low-voltage-driven thin film electroluminescence.