A method of stochastic simulation of damage and failure process of glass mat reinforced plastics is developed, and applies to examine the relation between the strength dispersion and the damage process. A stochastic model for composites having nonuniform distribution of fracture strength is first developed by the use of finite element method. The fracture strength of each element is specified randomly to follow the normal distribution. Then, the global damage process of the material is analyzed by incorporating this model into a finite element code of anisotropic nonlinear elasticity. The damage and failure process of glass mat reinforced plastics in uniaxial tension is analyzed, and the effects of strength dispersion on inelastic behavior and fracture modes are discussed in detail.