Photonic crystal fibers (PCFs) have attracted great interest in recent years due to their unique advantages over conventional fibers. The ability to design PCFs with very small core diameter offering opportunities for making fibers with unusual high nonlinearity. This can be used to design PCF-based Raman amplifier that is characterised by a short fiber length and operates at low pump power. In this thesis, Raman amplification characteristics in photonic crystal fibers are investigated in details. Performance comparsion between PCFbased Raman amplifier and other conventional fiber-based counterparts is investigated. The simulated results reported here can be used as a guide line to design PCF-based Raman amplifier that outperforms the conventional fiber amplifiers. The effect of various structure parameters on the performance of Raman amplifier designed using triangular PCFs is investigated. The results indicate clearly that both pitch and hole diameter should be chosen carefully to optimize the Raman gain in triangular PCFs. Raman gain as high as 33 dB can be obtained with a well designed PCF even at low pump power of 300 mW. All the results reported in this work are simulated using MATLAB 7.