Mesoporous sulfated zirconia nanoparticles (MSZNP) with high surface area have been synthesized by using sodium dodecyl sulfate (C12H25OSO3Na, SDS), both as a template and a sulfating agent via one-step route. On the basis of FT-IR, EDS together with NH3-TPD analyses, the SO42. anion, originated from the hydrophilic head of SDS, can be incorporated into ZrO2 to form MSZNP with super-acidity. The phase transition of ZrO2 from tetragonal to monoclinic phase was effectively inhibited by the presence of SO42., and the formation mechanism was illustrated in detail. MSZNP(550) achieved far higher activity than CSZ(550) in transesterification of soybean oil with methanol due to the synergistic effect of strong acidity, high BET surface area and the formation of mesostructure.