A classifying_coding system in point of extrusion aluminum_type materials based on the statistics and analysis of large numbers of extrusion aluminum_type materials section drawings.According to the Group Technology principle,using the variant design technique,a CAD system has been developed and used in a extrusion aluminum_type materials factory.The system can not only greatly shorten the products design time and reduce the product cost,but also rapidly retrieve extrusion aluminum_type materials section drawings.