The design of intake and exhaust port is a time consuming process in the engine development. It is important to reduce the time of this process in the DI diesel engine developmets. Basically, there are three time consuming parts in this process, which are the port geometry creation, CFD model creation, and making the experimental parts. Port development process is improved using automating technique for the geometry creation and mesh generation of CFD. The geometry creation is performed using CAD system IDEAS. The automatic geometry creation for the typical intake port shape as the directional and helical type are developed using the programming function of CAD system. The CFD code in which the automatic mesh generator is installed is used to predict the port performance from the CAD data. The port box for the experimental measurement is made using Rapid Prototyping. This system is applied to the typical conventional intake port to change the swirl ratio. It takes long to have a big change of swirl ratio by conventional method. The performance of the intake port created using this system is confirmed to rearch a good level comparing the conventional intake ports. The time to develop the intake port is drastically reduced.