Abstract: A model for angle-ply laminate Kirchhoff plate was developed based on the new modified couple stress theory. The new model contains only one scale parameter. The effects of ply angle on scale effect were analyzed. The principle of virtual work was employed to derive the bending equations and boundary conditions of laminate Kirchhoff plate in arbitrary ply angles. A simply supported antisymmetric microscale angle-ply laminate Kirchhoff plate was analytically solved by this new model. The results show that the scale effects of microscale anisotropic laminate not only depend on the characteristic size, but also depend on the ply angles. The ply angles may have significant effect on the scale effects.