Abstract: From the viewpoint of feature，product design is a process of feature transformation．But feature is mostly studied in the field of mechanical products and is nearly based on part-level in feature-based models available，which are difficult to support the design process of electrical-mechanical products such as communication products，etc．because of the high-lighting of shape，layout and human-factor．According to the shortages，this paper develops a concept and a product model of component feature which based on product-level for product layout design．