In this paper the matrix displacement method is employed in analyzing car body structures. The finite element method treats the car body as arbitrary shells, whereby idealization of the car body structure becomes possible. The paper takes into consideration not only the plane stress, but also the bending stress. The program details which include an automatic input and output are described.The first calculation example shows a comparison between classic and present analyses of plates and shells, demonstrating the satisfactory accuracy of this method. The next example shows an application to the whole and local structures of an actual car, a technique which makes possible reasonable body design analysis.