With the water as the solvent, zinc propionate (C6H10O4Zn) was successfully synthesized from propionic acid and zinc oxide as the raw material by microwave and conventional hydrothermal methods. The effects of reaction temperature, time, molar ratio of propionic acid/zinc oxide and dosage of deionized water in the two synthesis process on the yield of C6H10O4Zn were studied through parallel experiments. The product was characterized by means of EDTA complexometric method, EA, FT-IR and TG. The results showed that the yields of C6H10O4Zn by microwave and conventional hydrothermal methods were 94.06% and 87.34%, respectively, under the optimal synthetic conditions. Compared with conventional hydrothermal method, microwave hydrothermal method had a great strengthening effect on synthesis of C6H10O4Zn. The synthesized product possessed the typical structure of C6H10O4Zn, and the composition of C6H10O4Zn was nearly the same for the two synthesis methods. However, C6H10O4Zn obtained by microwave hydrothermal method had more crystallization water and better thermal stability than that from conventional hydrothermal method.