A series of Zn-Mg mixed oxide catalysts with different Zn/Mg molar ratios were prepared by coprecipitation method for the glycerolysis of soybean oil to produce monoglyceride. These catalysts were firstly characterized by XRD, BET, SEM techniques, and the base strength and basicity of catalysts were determined by Hammett indicators. The reaction conditions were then optimized for the preparation of monoglyceride catalyzed by Zn-Mg mixed oxide catalyst. The reusability of Zn-Mg mixed oxide catalyst was studied finally. The results show that changing the Zn/Mg molar ratio can control the base strength, basicity, surface area and pore volume of Zn-Mg mixed oxide catalysts. The activities of Zn-Mg mixed oxide catalysts with different Zn/Mg molar ratio are consistent with the change of basicity, surface area and pore volume, and the maximum activity could be obtained when the Zn/Mg molar ratio reached 0.1. The optimum reaction conditions were as follows: n(glycerol):n(soybean oil)=3:1, reaction temperature 210?C, reaction time 2 h, and catalyst amount 0.6% (base on the mass of soybean oil). Under these conditions, the soybean oil conversion and monoglycerides yield can reach 95.6% and 58.5%, respectively. After recycling five times, the soybean oil conversion remains 80.9%, which means the ZM0.1 catalyst is stable.