Because of their high specific stiffness and strength, composite materials have been used in the structural of vehicles to provide a competitive advantage of through weight reduction while maintaining or even increasing functionality. Composite materials have been used for IP carrier which forms the skeleton of the cockpit and provides the base architecture off of which IP components are attached and function. Specially, composite materials using injection molding process have been used to develop IP carrier recently, due to high level of styling flexibility by that can achieve high degree integration and simplicity of process. However, for injection part especially for large part would deform largely. Consequently, deformation controlling is very important for large composite part that used injection molding. In this study mold flow analysis was conducted on the composite IP carrier structure which gets from the topology optimization result. The investigation consists of injection method, molding process and the position that would deform largely. The molding process was set and the positions deforming largely were found out. Structural optimization was done to control the deformation within the requirements. Mold flow analysis result for the optimization structure showed that deformation of crucial position were within the requirement. After that, 3D scanning test and composite IP carrier assembling were conducted to verify the CAE simulation result. The simulation result can met with the 3D scanning test result, and the composite IP carrier can be assembled to vehicle successfully.