The in-situ application results of comb-shape polyacrylamide showed that the comb-shape polyacrylamide can increase the viscosity value of 58 percent to 81 percent more than that of the ordinary Daqing polyacrylamide,and 22 percent to 70 percent more than that of the ordinary polyacrylamide MO??4000 produced by Japan,under the same conditions.The oil displacement efficiency of comb-shape polyacrylamide can increase by two times compared with that of the ordinary polyacrylamide.At the same time,it can decrease the polymer dosage by 30 percent more than the ordinary polyacrylamide.The excellent economy,social and environment benefits of comb-shape polyacrylamide for polymer flooding,alkaline-surfactant-polymer flooding and cross-linking polymer flooding have been achieved.It has become an excellent high-efficiency oil displacement agent and profile modification agent for oilfield exploitation.