The stability of non-Newtonian fluid confined between two concentric rotating porous cylinders has been examined. The critical determines the on set of instability has been determined as a function of 'a' (wave length) and S (cross viscous parameter). The variation of the critical Taylor number with S, suction parameter lambda and radial velocity distribution have been shown. It has been found that the effect of suction at the outer cylinder is to stabilize the flow whereas the injection destabilizes the flow. The presence of suction or injection does not affect radial velocity curves or vortex cells