For this paper, the design criteria of elliptical or cross sectional shape for runner system will be introduced, and a comparison between round shape and semi-elliptical shape of runner system will be conducted. To the authors best of knowledge, many attempts have been taken in injection molding for process parameters and material characteristics, however for injection system which includes runner, gate, and sprue, there are a few publications, but there is no reference to analyze and simulate the elliptical cross sectional shape of runner system. In this paper, the structure of runner system is simply introduced and advantages of elliptical runner will be evaluated. Then, the injected part with runner and gate system is designed via SolidWorks. For accurate result of simulation, FEM is considered via SolidWorks Plastic.