Dynamic stresses acting on a link depend upon the area of the section of a link and the forces acting on the section, and the inertia forces and the inertia torque depend upon the distributions of masses of a link and the shape of a Link. Therefore, it is important to design the shape of section of a link for improving the distribution of the stresses of links and reducing the weight and the shaking force and the shaking moment of the mechanism. This paper presents a design method of the uniform strength links in a planar link mechanism. The design examples are given and the dynamic characteristics are eatimated.