In this paper we have considered the oscillatory flow performing small harmonic oscillation in a channel of gap h. Our analysis is based on Ishigaki5,6 work in which, he has assumed the stream unsteady flow with its conjugate complex part. We obtained the amplitude of the fluctuating velocity gradients its variation with respect to transfer magnetic field. An exact analysis of oscillatory MHD Couette flow has been performed by using series solution method. Numerical calculations are made for phase angle and shearing stress of the unsteady MHD flow in a horizontal channel for various values of Hartman number.