Matrix crack and fibre breakage are the main damage models of the fibre reinforced polymer (FRP) laminates under cyclic loading. In this paper, meso-mechanical analysis is used and a two-parameter model is developed to describe the stiffness reduction. Based on the probability distribution function of fiber strength, the evolution of fibre breakage is deduced. Then with the help of the damage evolution, the stiffness reduction of laminates can be predicted. As an example, the stiffness reduction of grass fibre reinforced polymer (GFRP) laminate is made and the simulation results show that the proposed model has good capacity to describe the stiffness reduction of FRP laminates resulted in the combination of matrix crack and fibre breakage.