Abstract: In order to predict the elastic coefficients of composite single layer laminate containing voids, the unidirectional fiber reinforced composite single layer laminate were used as research object, and based on mesomechanics method, a prediction method for elastic coefficients of composite single layer laminate containing voids based on two-scale representative volume cells was proposed firstly. Then, based on the fibers distribution and void feature, representative volume element model on the fiber-matrix scale and representative volume element model of the composite single layer laminate containing voids were established, and finite element method was employed to solve the elastic coefficients. After that, with the periodic symmetry boundary conditions applied, the first step of equivalent was conducted on the fiber-matrix scale, thus the elastic coefficients of composite single layer laminate without voids were obtained. Finally, the second step of equivalent was conducted on the representative volume element model of composite single layer laminate containing voids, and the prediction for elastic coefficients of composite single layer laminate containing voids was finished. The results show that the calculated results obtained by using this method agree well with the test data. With the combination for elastic coefficients of fiber and matrix as well as the model of voids morphology, the method can reflect the effects of each factor on the elastic coefficients of composite single layer laminate.