This chapter focuses on the solitons in a fiber Bragg grating. Solitons can be propagated without any distortion, if the nonlinear characterstics (like amplitude and hence intensity, depending on velocity) and dispersion characterstics (frequency depending on velocity) of the media are balanced. Soliton type propagation is possible only with single mode fiber (SMFs). It reviews the fundamentals of Fiber Bragg Grating (FBG) and considers the nonlinear pulse propagation through the same area where the pulse propagation is governed by nonlinear coupled equations. Solitons existing in FBG have been investigated in detail. Based on the pulse spectrum with respect to PBG, solitons in FBG were classified into gap solitons and Bragg grating solitons. A simple method to obtain the explicit analytical gap soliton solutions to the nonlinear coupled-mode (NLCM) equations has been developed. Though the use of solitons for communication seems advantageous, they do pose some technical difficulties. The current electronic amplifiers and switches just cannot respond quickly enough for these short soliton pulses of high speed. © 2006 Elsevier Inc. All rights reserved.