In this paper, the Shape influence of piezoelectric beams including triangle, trapezoid, rectangle, invertedtrapezoid, convex parabola, concave parabola, and comb-Shaped (a combination of two triangular beams with aconnector of 4 mm length) are addressed and analyzed by FEM. The analysis is performed for a bimorphpiezoelectric beam. The analyzed parameters include the beam length, thickness and width of the piezoelectriclayer. The study is performed using COMSOL Multiphysics software for all seven Shapes. The results show thatdue to the mechanical properties of the beams, the natural frequency of the triangular beam is more for allconsidered parameters. In addition, as the width of the beam end increases, the natural frequency reduces, too. Since natural frequency is inversely related to electric power, the inverted trapezoidal beam has the highestelectric power and the triangular beam has the lowest one.