Drag reduction achieved by introducing minute amounts of high molecular weight linear polymers into aqueous solutions has been investigated using a rotating disk apparatus. The drag reducers used in the current study are poly(ethylene oxide) and poly(acrylamide). The dependence of drag reduction on various factors such as polymer molecular weight, polymer concentration, rotational disk speed and temperature has also been studied. Further, studies on polymer degradation are given by simultaneously measuring decreases in the drag-reducing effectiveness and the viscosity-average molecular weight of the polymer solution. Drag reduction is found to increase with polymer concentrations, reaching a maximum at its critical concentration. At low polymer concentrations, polymers of higher molecular weight produce greater drag reduction. Polymer degradation due to high shear force in the process of drag reduction is also found to be more apparent at lower polymer concentrations. Furthermore, tests on thermal effect show that poly(acrylamide) is more thermally stable than poly(ethylene oxide).