The study of wave transmission over submerged obstacles and the flow pattern that formed around the obstacle has been always an important subject because of the affect directly on wave and the changes in wave energy that is crucial in the design of devices, which absorb wave’s energy and coastal breakwaters. In this research, the flow pattern induced by solitary wave passing over a submerged vertical thin plate has been studied. A wave maker piston has been used to generate the solitary wave and particle image velocimetry (PIV) technique has been used to flow visualization that this technique is non- introsire optic method, which can measure the fluid velocity with any changes in flow pattern. The study of the flow pattern visualization, velocity values and vorticity shows, at first the flow separation shear layer forms and the clockwise vortex generate at the rear edge of the obstacle before the wave arrives to the barrier. Then the vortex grows in size and cussed the water move upward like vertical jet on upstream. Then the fluid enters to the downstream and generates the counterclockwise vortex in this region, which is less than the first clockwise vortex in power that makes an important difference with the thick geometry researches. In addition, the non-dimensional horizontal components of fluid velocity at the time of shear layer formation at the rear edge of the plate have been studied and it has been compared with the case that the barrier is rectangular.