A complex system that consists of cetyltrimethylammonium bromide (CTAB), Triton X-100 (TX-100), and hydrolyzed polyacrylamide (HPAM), differing from the old-time conceptions of the displacement system, has been studied. It is indicated that the complex system is capable of satisfying requirements of high viscosity and low interfacial tension under conditions of higher temperature and mineralized water. The dynamic interfacial tension of the complex system depends upon multifarious factors, such as the ratio of TX-100/CTAB, concentrations of HPAM and surfactants, temperature, and the mineralized degree, etc. Especially, it is interesting that the dynamic interfacial tension of the complex system cannot reach an ultralow value (< I x 10(-2) mN center dot m(-1)) when one component is lacking among the HPAM/TX-100/CTAB complex system. From the results of the adsorption on quartz sands and on the core flooding tests, it can be concluded that the HPAM/TX-100/CTA-B complex system is suitable for use as a displacement system in an oil field after polymer flooding.