This paper is concerned with deformation analysis of diaphragm-type air springs for railway vehicles, which consist of six layered nylon fiber-reinforced rubber composite, rubber linings and steel wire bead parts. The analysis has been carried out with a finite element code developed to consider the orthotropic properties of fiber-reinforced rubber lamina, geometric non-linearity by large deformation, and contact between an air bag and a bead ring. The analysis provides vertical spring characteristics of an air spring, which are the variation of the vertical force, the volume of an air bag and the internal pressure with respect to the vertical deflection.