With the development of small and low-power electrical equipment, a great amount of efforts has been made to replace the battery with a useful power supply. Meanwhile, the use of environment vibrational energy to supply the electrical power of these equipment motivate many scientist to carry out research in this field. In general, the transformation of vibrational energy into electrical energy can be done in three different ways, namely, by use of piezoelectric, electrostatic and electromagnetic. In present study, the energy harvesting from the non-linear vibrations of an L-shaped beam with the use of piezoelectric patches is evaluated. The beam was assumed to be an Euler-Bernoulli in which the effects of rotational inertia and shear force are neglected. Also, the effective mass of the beam is assumed to be in the top of the beam. The axial displacement of the beam is also considered with the assumption of small excitation amplitude. The effect of the piezoelectric patch on the equations of motion is also considered. In this research, nonlinear motion equations of L-shaped beam are extracted by use of Lagrange method and they obtained equation of motions are solved by multiple scales technique. Also, the mode shapes of the system are calculated for the linear undamped system. The dimensions of the L-shaped beam are chosen in such a way that the ratio of the first-to-second natural frequency is 1 to 2, in order to increase the range of the energy harvesting frequency. Finally, the results of the analytical solutions are compared and validated with the results obtained from experimental and finite element. Good agreement was observed between the theoretical values and experimental data. Keywords: energy harvest, L-shaped beam, nonlinear vibrations, piezoelectric.