In this study, thin film of titanium dioxide (TiO2) was deposited onto n-type silicon substrate by radio frequency (RF) magnetron sputtering system. The admittance (capacitance and conductance) measurements were performed in the frequency range of 500 Hz - 500 kHz and at room temperature. The dielectric parameters such as dielectric constant (epsilon'), loss (epsilon ''), loss tangent (tan delta), ac conductivity (sigma(ac)) and complex modulus (M*) of the MIS structure were obtained from these measurements. While the C value decreases with an increase of the frequency, the G increases. The change in C and G with frequency is attributed to the presence interface states. The value of epsilon' and epsilon '' decreases with increasing frequency. On the other hand, the value of conductivity increases with increasing frequency.