In optical communication system to compensate dispersion Fiber Bragg grating (FBG) is one of the applicable and important components. Here we are calculating best amount of parameters by simulating the model and then observe the effect of this component in data receiver. To tackle the non linear effects of transmission system Fiber Bragg grating has been employed with optisystem software very length. The analysis based on the chromatic dispersion. An analysis of optical System with FBG and without FBG length of 60 to 80km. We are design without FBG length of 60km which is generate ber 10-9 and Provide best dispersions and with FBG its very up to 80km and achieve best output of the system. We used FBG length 27mm chirp parameter 0.0007. Propagated light in a FBG core which satisfies the Bragg conditions is resonated by grating structure and reflected. The distance between gratings specify the reflected wavelength, so that, reflected light in Bragg wavelength is removed from transmission spectra.