A new kind of surfactant, fatty alcohol polyoxyethylene ether propionate ( symbolized as AEP), was synthesized with fatty alcohol polyoxyethylene ether, methyl acrylate , sodium hydroxide as raw materials. The structures of them are characterized by IR and MS. The surface tension and oil-water interfacial tension have been measured. The results show that the cmc and γcmc of C12AEP respectively are 0.236 mmol•L-1 and 26.63 mN•m-1 at 25℃. The micropolarity of the surfactant also are determined from the ratio of intensity of peaks(I3/I1) of pyrene fluorescence emission spectrum.The I3/I1 of C12AEP micelle shows that its micropolarity is smaller than that of traditional surfactants.The interfacial tension of AEP is influenced by hardness, salinity and the proportion of complex systems by mixing with amphoteric surfactant (B) . Ultralow interfacial tension of 3.98×10-3mN/m can be formed in the water-oil interface ,so AEP can be applied to the three exploitation of oil.