This research applies 3D mesh mold-flow analysis to analyze the SD (Secure Digital) card. It aims at temperature of the mold and plastic. The proper mold filling temperature is found by simulation analysis to improve the short shot situation, and seeks the cause of warping via various processed conditions. SD memory card clip has a big variation in thickness. Due to the bigger flow resistance the plastic is difficult to reach thinner portion, even hot plastic is also difficult to supply. The temperature of plastic goes down as a result of the cold mold cavity. Thus, the plastic does not reach certain portions before solidifying. The cooling system of injection machine was controlled by constant temperature oil cooling. This study explored the optimum injection condition by utilizing experiment to control the temperature of the plastic, the temperature of mold, the packing pressure process and so on. It is valuable to companies which utilize injection mold applications.