In this paper, we have to demonstrate the chromatic dispersion [CD] monitoring by a differential phase shift method using Kerr phase interrogator. Kerr phase interrogator, which investigates the phase shift between two sinusoidally modulated optical signals utilizing Kerr effect that are carried by two different laser wavelengths. The simulated design of this paper analyses the power variations of first order sideband as a result of nonlinear interactions and also can explain the CD impact of Kerr medium. The Kerr phase interrogator based technique for measuring phase shift is a promising approach for monitoring and sensing applications. The simulated model of proposed system has been implemented by using Optisystem software and verifies the results obtained from various discussions.