Mold design for in-mold coating were carried out in order to achieve simultaneous coating and injection molding of an automotive armrest. The developed mold consists of two molds and one sliding plate. The first mold includes a movable mold piece and a first fixed mold piece for injection molding of a substrate. On the substrate surface near a parting line, sealing edges were considered for forming a seal projection. The second mold includes the movable mold piece and a second fixed mold piece for forming the coating. The mold enables coating on the substrate surface after injection molding. The materials used were PC/ABS for substrate and 2-component Polyurethane for coating. The experiments were conducted by changing the flow rate in order to investigate mixing characteristics. As the flow rate increased, the mixing was more improved. And the bubbles appeared over the substrate surface decreased with an increase of the weight of injected coating material.