Abstract: Zinc acetylsalicylate was synthesized by solid-liquid phase reaction with the starting materials of ZnSO4•7H2O and acetylsalicylic acid (ASP). The product was characterized by X-ray powder diffraction，FT-IR and DSC. The X-ray powder diffraction data indicated that the crystal structure of the complex belonged to monoclinic system. The lattice parameters are a = 1.1449 nm，b = 1.4048 nm，c = 0.9247 nm，β = 94.46°. The optimized conditions for the synthesis are n(ASP)∶n(Zn2+) = 2∶1，pH = 6，reaction temperature 80 °C，and reaction time 30 min，with which the yield of zinc acetylsalicylate is 82.5%.