The interfacial electrical properties of InSb MIS structure with low temperature remote PECVD SiO₂ have been characterized. The interface-state density at mid-bandgap of the MIS structure was about 1∼2 x 10^(11) cm^(-1)eV^(-1), when the SiO₂ film was deposited at 105℃. However, large amount of interface states and trap states were observed in the MIS structure fabricated at temperatures above 150℃. The time constant of 10 ^(-4)∼10^(-5) sec of interface states was extracted from G-V measurement. As the deposition temperature increased, the hysteresis of C-V curves were increased due to the high trap density.