In this paper, we present a study of thermal, change in index of refraction and stress in photonic crystal fiber (PCF) lasers with the tow-end pump scheme. We show the effect of the tow-end pump scheme, small length of fiber and the large radius fiber on the beam quality is the most suitable choice compared to large length and small radii of fiber. In addition, we show that management of thermal effects in (PCF) lasers will success of scaling up efforts and determine the efficiency.