Abstract: The structure of micro injection mold was optimized on the basis of the CAE analysis, and the feed system, venting system and temperature control system were optimized according to rheological data of polymer by the Autodesk Moldflow Insight software. These results were used as a reference to conduct the design of micro mold. The μIM parts were molded successfully to verify the accuracy of optimization process, and the experimental results obtained compared with short shot micro parts was in good agreement with those from the CAE ones. The melt shape appearing at the flow front seems to be flush due to the micro-sizing effect.