The phase diagrams of lyotropic liquid crystal and the structure of lamellar liquid crystal were studied in ionic surfactant (sodium dodecyl surface, cetyl trimethylammonium bromide) and nonionic surfactant (polyoxyethylene oleyl ether,polyoxyethylene nonylphenol) mixture systems.The nonionic surfactant with smaller polar group mixed with ionic surfactant tend to form lamellar liquid crystal,in which the phase behavior of the nonionic surfactant is similar to the fatty alcohol mixed with ionic surfactant.O...