Injection molding is one of the most important polymer processing methods for producing plastic parts. Many factors affect the molding process and the plastic part quality. Previous attempts on prediction and process planning of injection moldings are mostly based on empirical methods. Now with the help of finite element analysis, designers can reduce costly experiment and shorten development cycle, and correctly solve manufacture problems, such as material property, product design, and mould production. Best injection location is obtained by MoldFlow analysis. Fill time, weld line, air trip are deeply studied. The simulation provides scientific and valuable injection process information and helps engineers to take right decisions when they develop the tools. At last, a mould for water kettle handle is designed, and the NC machining of the mould cavity is programmed by UG NX software. (4 pages)