Abstract: The aim was to optimize the extraction process of chlorogenic acid from Lepisorus ussuriensis (Regel et Maack) Ching. The hot water was used to extract chlorogenic acid from Lepisorus ussuriensis (Regel et Maack) Ching. According to Box-Benhnken central composite design principles, three factors and three levels of response surface analysis tests were designed to determine the optimum extraction conditions of chlorogenic acid from Lepisorus ussuriensis (Regel et Maack) Ching. The results showed that the best extraction process of chlorogenic acid was as follows: liquid to material ratio was 25:1, extraction time was 4 min, and extraction temperature was 96℃. Under such condition, chlorogenic acid yield was up to 5.11% and close to the theoretical value, indicating that the hot water extraction process had good results with the response surface methodology to optimize the extraction process of chlorogenic acid from Lepisorus ussuriensis (Regel et Maack) Ching. The water extraction had characteristics such as low energy consumption, short time and low cost, which provided theoretical basis for industrialized production of chlorogenic acid from Lepisorus ussuriensis (Regel et Maack) Ching.