Most of hydroelectricity development represented by the dam in our country has almost completed. In comparison with it, the use of ocean energy generation is still a development stage. For this reason, we aim at development of the small hydroelectricity device using a piezo-electric element, it will harness Kármán vortex street which occurred by put the object in flow. In this paper, we perform basic examination by numerical simulation and hydraulic experiment about the relationship between Kármán vortex street and the object shape in flow, and vortex-induced vibration. Then we will make generation experiment based on its results, and suggest suitable model of generation.