Abstract: The paper systermatically studied the varitional pattern of tenderness of steamed chicken legs under various temperature and time conditions, by using sensory examine and physics survey methods, and the influence to tenderness of tenderization by the hydrolysis of collagen to gelatin and the separation of muscle fiber and of tough action by the coagn-lation of muscle fiber protein. The result shows that the results of sensory examine and physics survey have good corelation, the heat and time isotherms accord with Y =aXb, the best temperature and bine of steamed chicken sensory accord X(t) = (a’/a) (1/b) X(b’/b)(T), the influence of heating protein to tenderness accord Y = K + aXb.