The paper investigates nonlinear dynamical characteristic of a macro fibre composite （MFC） plate subjected to transversal excitations. Nonlinear governing equations for the MFC plate are established based on Reddy''s first-order shear deformation theory， von Karman geometrical nonlinear kinematics and Hamilton’s principle. To analyze complex inner resonance phenomenon of the MFC plate， the first three order natural frequencies and the relationships of various internal resonances with different physical dimensions are discussed under different order excitations， and Galerkin’s approach is employed to discretize the partial differential governing equations into a three-degree-of-freedom nonlinear system. Then， stability analysis is conducted to investigate influences of related parameters on nonlinear behaviors of the composite plate. The results of numerical simulation show that increase of plate size will lead to decrease of both the natural frequencies and dynamic stability of the plate. Moreover， the different order transversal excitation has great effects on the nonlinear dynamics of the structure. The results will provide theoretical supports for practical engineering applications.