Abstract: The catalyst nickel supported on active carbon (Ni/C) was prepared by isometric wetness impregnation method and characterized by BET and XRD measurement. The effects of preparation conditions on the performance of the Ni/C catalyst for vapor phase carbonylation of ethanol were investigated. The results showed that the catalytic performance of Ni/C is strongly influenced by the preparation conditions; the optimum preparation conditions are: Ni loading of 5%, pretreatment of active carbon with water, pH value of impregnation solution within the range from 8.0 to 9.0, calcination temperature of 450℃, and H₂ reduction temperature of 400℃. Over the catalyst prepared under the optimum conditions, the conversion of ethanol and the selectivity to propionic acid reach 96.14% and 95.71%, respectively.