Abstract: n order to investigate the application of numerical simulation in the mould conceptual design and process determination for the plastic injection process, the role and technical routine of computer aided engineering(CAE)in plastic injection mould design and related process planning was discussed based on a practical case. The assessment and optimization method of this technique for flow runner and cooling system design were introduced. The approach of using CAE technique for injection plan design during mould design stage is presented. It showed that this method could effectively predict the rationality of filling pattern and the potential defects caused by the improper mold design and injection process,determine air trap location，configure the cooling system and evaluate its rationality, and thus an effective way to shorten mould design cycle and improve mould design quality.

Key words: mould, plastic injection process, computer aided engineering, conceptual design