Woven fabric composites with spread tow may induce better resin impregnation and mechanical properties than the conventional woven architectures. However, the mechanism of damage development of woven fabric composites with spread tow has not been investigated. To investigate the effect of spread tow on the damage development, we have developed the numerical simulation of the mechanical behavior based on damage mechanics. We have prepared two numerical models with a distribution of volume fraction in a strand, and an effect of the volume fraction in a strand on the damage development has been investigated. The numerical results indicate that the location of occurrence and the type of propagation of transverse cracks are quite different. Furthermore, the mechanical behaviors of woven fabric laminates with three layers with distributions of micro volume fractions in fiber bundles have also been analyzed. In this paper, the numerical results of the damage states are described.