Artificial knee joint capable of preventing dislocation of thighbone coupling member

The present invention relates to an artificial knee joint that comprises a thighbone coupling member and a bearing member and prevents the dislocation of the thighbone coupling member and, more specifically, to an artificial knee joint that: comprises an upper surface, on a post thereof, which performs a motion relative to a cam of a thighbone coupling member; prevents the cam of the thighbone coupling member from deviating from the inflection point between an upper curved surface and a lower curved surface by making the radius of curvature of the lower curved surface larger than that of the upper curved surface that exists on a portion extending rearward from the upper surface; and enables the thighbone coupling member to return while naturally descending along the upper surface, which is inclined at a predetermined angle, even in a case where the thighbone coupling member is dislocated, thereby preventing an increase in the amount of bone to be cut while increasing a jump distance.