Abstract: This study aims to analyze the vibration characteristics for cantilever plate under pre-stresses. The effect of gravity (self-weight) of cantilever plate, side fluid pressure with different immersed ratios and direct tensile and compressive force are taken into account. The natural frequencies and mode shapes are obtained with and without the pre-stresses. The effect of gravity was studied during (180°) angle of support starting from vertical downward support to vertical upward support. Then the effect of side fluid pressure was studied for fully, partially and non-immersed cases. Also, the effect of direct tensile and compressive forces acting at the tip of the plate in the direction parallel to the plate axis, was studied to find the effect of the force on the natural frequencies. The numerical Finite Element Method (FEM) is used in the analyses by using the ANSYS Workbench Software using the interaction between (structural static) and (modal) analysis. Two plates with different material are used in the study with the same geometry as a uniform rectangular plate to analyses the gravity and side fluid pressure effects and only one plate used to analyses the direct force effect. For the self-weight problem, the tension effect tends to increase the natural frequencies but the compression effect tends to decrease the natural frequencies because of the buckling tendency and in the case of pure bending which means that the tension at the upper surface and compression at the lower surface are equals, the natural frequencies remain the same as in the case of no gravity effect. For the side fluid pressure problem, the contact with fluid tends to decrease the natural frequencies. Then for the direct force cases in the tensile case the natural frequencies were increasing and in the compressive case, the natural frequencies were decreasing. For all cases, the mode shapes still the same with and without pre-stresses. All results compared with the results without pre-stresses.