We present a precise cell trapping platform, structure-confined electrophoresis, which utilize microchannel with lateral cavity to bend the electric field for generating positive dielectrophoresis (DEP) force. A revealed metal electrode, 10μm × 20μm, is placed inside the deep place of cavity. Providing stronger DEP force to trap mobile cells and reducing the flow shear stress acting on the trapped cell are two advantages of the cavity design. The cells trapping efficiency are increased by the multi-channel design. Five microchannels provide 400 cells trapping locations. Finally, we calibrate the relationship between flow velocity, applied ac voltage and the trapped cells number. This application utilizing structure to confine the electric field distribution is not only to provide the accurate cells trapping function, but to be a platform for electrical fusion approach of trapped cells.