Abstract: Inulin was extracted from Jerusalem artichoke by ultrosonic-assisted hot water extraction method. Compared with hot water extraction, inulin extraction yield can be increased by 16.70% through ultrosonic assisted method, and the effect is remarkable. It was concluded from single factor experiment and orthogonal mothod that the optimal condition of extraction was ultrosonic treatment for 25 min at the power of 112 W before marinated at 100℃,the mass ratio of material to water being 1：15. Under this condition, the extraction rate was 70.05%. The orthogonal factors affecting ranked : water bath extraction temperatureultrosonic extraction power跃ratio of material to water跃ultrosonic extraction time.