A flexible robot arm with strain gauges distributed on it is used as a sensing unit in determination of endpoint position and force of flexible manipulator. The position and orientation of the flexible arm is expressed as a function of the local curvature. An interpolation technique gave a continuous curvature function from a finite set of measurements made with strain gauges. The endpoint force and moment depend not only on the local strains but also on the positions and orientations of the endpoint and those points where the strain gauges are located. Using the measured strains, one obtained the endpoint position and orientation as well as endpoint force and moment of the flexible arm. The experimental results demonstrated the effectiveness and accuracy of the proposed approach.