In this paper, the Patatin protein was extracted from potato fruit juice, and the enzymatic properties of Patatin protein as ester acyl hydrolase were studied using p-nitrophenyl acetate as the substrate. The results showed that the lipid acyl hydrolase had the highest activity at 37 ℃, and had thermal stability at 40～50 ℃. The enzyme was inactivated after treatment at 70 ℃ for 120 min. The optimal pH of lipid acyl hydrolase was 8.2. The lipase activity was activated by Fe²⁺, Fe³⁺ and Mg²⁺ , inhibited by K⁺ and Ca²⁺ . In addition, low concentration of Al³⁺ and Zn²⁺ were promoting the hydrolysis ability of lipid acyl hydrolase and the high concentration of Zn²⁺ inhibits the activity of the lipid acyl hydrolase. The results of this study will provide some new scientific theory guidance for the development and utilization as well as its functional property of the Patatin protein.