Abstract: Since the generalized conforming element has been put forward, a number of plate elements with good performance are announced and widely used. Meanwhile the dynamic analysis of plates is limited to the thin plate. Long Yu-Qiu and Fu Xiang-Rong proposed a generalized conforming quadrilateral thick plate element ATF-PQ4b which uses the polynomial analytical solution of governing equations of Mindlin-Reissner plates as trial functions. In this paper, the element is employed to calculate the natural frequencies and modal shape of plates by the program coded by MATLAB. Numerical examples show that the generalized conforming quadrilateral thick plate element based on analytical trial functions is simple and efficient.