The formation and structure of the steady barotoropic flow over the shallow shelf slope are investigated using the theory with linear bottom friction and the numerical experiments with quadratic bottom friction. The barotropic flow over the shallow shelf slope, which is controlled by the bottom friction, has the balance between bottom stress curl and vortex stretching of water column. Such flow cannot conserve its volume transport to the downstream due to the onshore or offshore flow. The formation of barotoropic flow is related with the coastal-trapped wave propagation, i.e., Kelvin wave or topographic Rossby wave, during the transient period like as the geostropic adjustment. Therefore, the steady barotropic flow is formed in the direction of wave propagation, i.e., at the right hand sidewall to the source of disturbance in the northern hemisphere. By using the numerical model in which the ideal topography around the Tsushima/Korea Strait is taken into account and the flow system is driven by the sea level difference between the East China Sea and the Japan Sea, the flow patterns in winter are considered. In result, two branches in the central part of the East China Sea can be simulated. One northward branch is clockwise-flow along the isobaths in the northern part of the East China Sea and the other eastward branch directly inflows into the Tsushima/Korea Strait. Key words: barotoropic flow, shallow shelf slope, bottom frictio
