Abstract: One of the most common methods in producing plastic products is injection molding for many purposes ranging from a daily product to high-tech equipment. This paper is to display how to design a complete mold and to examine the material, forecast the possible defects, and optimize the design to achieve the maximum outcome of the products with minimum cycle time in each production cycle. The CAD/CAM software is applied as the analysis tool for the particular chosen product “Clothes-hanger”. In this paper, it will describe the behavior of plastic material starting from the filling phase until the end of the cooling phase in the injection process. The final result shows the possibility of having cavity designs of “Clothes-hanger” in one mold plate of the size 330mm×458mm×53mm.