The MI(Mognetoimpedance) effect related with the magnetic property has been investigated in in mumetal thin film prepared by using R.F magnetron sputtering method. Ni81.1Fe14.2Cu1.9Mo2.8 wt % mumetal thin film is low coercivity (0.4 Oe) and high effective permeability(3000). The depth of the double peaks in MIR (magnetoimpedance ratio) curve is in inverse proportion to the thickness of the sample and is proportional to the frequency. MIR is increased up to 36.5 MHz and then decreased with the increment of the measured frequencies. The maximum MIR of the as-deposited sample and the thermally treated sample were 75% and 70%, and the MI sensitivities measured at 36.5 MHz were 29%/Oe and 40%/Oe, respectively. The depth of the MIR curve in mumetal film was improved with the increasing of the magnetic anisotropy.