As the main index of the physical and mechanical properties of rice ,grain and grain handle connecting force is an im‐portant factor to measure the degree of difficulty of threshing .In this paper ,tests of connecting handles between the rice grains and the grain handles of 14 kinds of high‐yielding rice in Hunan have been done .Research on the curve of the relationship be‐tween connection force and displacement ,got the valley handle connected power distribution ,and got the relationship between yield and connecting force of high‐yielding ...