A two-dimensional (2-D) hybrid simulation is carried out to study the formation and structure of the reconnection layer at the dayside magnetopause. The result is shown for a case with a zero guide field (By=0) in the magnetosheath and magnetosphere. A quasi-steady reconnection layer develops behind a leading transient bulge in the outflow region of the reconnection, in which an intermediate shock is present on the magnetosheath side. The structure of the intermediate shock varies with the distance from the X line along the magnetopause. An accelerated plasma flow is present in the boundary layer on the magnetospheric side of the intermediate shock. The ion transport across the magnetopause boundary layer during the formation of the reconnection layer is also investigated. ¿ 1997 American Geophysical Union