Abstract: Firstly，the definition of Part View is presented．The hidden relations of Part Views are established by given a depth value to a Part View in a product assembly drawing．Then the inside boundaries and an outside boundary of the Part View are obtained by using automatically recall-based searching algorithm referring a point．Therefore，hidden relations of Part Views can be regarded as the hidden relations of the boundaries of Part Views in different parallel planes．Furthermore，establishing the virtue display data from the entity data and processing the virtue display data by a simple hidden algorithm，we can obtain the hidden display or printing drawings of the product，and keep the integrity of the product data．This method has been used in the Mechanical Design System (GHMDS1.0) successfully.