An asymmetric Gemini surfactant, comprising two nonidentical hydrocarbon chain lengths and two different anionic hydrophilic groups, abbreviated as C12CO2Na-p-C10SO3Na has been synthesized through Williamson etherification, sulfonation and saponification. Ethyl 2-bromomyristate and 4-decylphenol were used as the starting material. The structures of main intermediate products and the title product were characterized by FT-IR and 1H NMR. The optimum conditions for etherification were n (ethyl 2-bromomyristate) : n (4-decylphenol) = 1.05:1, K2CO3 as acid binding agent, DMF and toluene as solvent, and refluxing for 3 h. The yield of ethyl -(4-decyl) phenoxytetradecanoate was 77.2% (basing on 4-decylphenol). The surface activity of C12CO2Na-p-C10SO3Na was measured by Wilhelmy method. The surface tension could decrease to about 26 mN/m, and the critical micelle concentration (CMC) was found to be 3.28×10-6 mol/L. The CMC value was nearly 3 orders of magnitude lower than that of the corresponding traditional surfactants, such as sodium myristate and sodium m-decylbenzene sulfonate. The results illustrated that the asymmetric anionic Gemini surfactant show high surface activity.