We studied the propriety of finite element method (FEM) analysis by using the Mooney-Rivlin quadratic model. A Mooney-Rivlin number can be analyzed by software attached to FEM software. But the degree of agreement with an experimental value is poor. And software is in a black box. Therefore, we had to originally develop an analysis software anew. The measurement data are tensile test data of one axis. As for the Mooney-Rivlin quadratic model, calculation is complicated, but the precision and the power of expression are good enough. About the deformation force of a product, the calculated value agrees well with measured value.