To provide the orientation information of gear-boxes in the machining center, an algorithm was studied. The gear-box part was built based on dozens of parameterized features according to KBE (Knowledge Based Engineering), and was assumed being surrounded by six planes which were Front, Back, Left, Right, Bottom and Top. The features based on KBE were applied to the six planes one by one through the Boolean operation. Each feature was set a direction vector parameter which showed the feature orientation in the global coordinate system. After each direction vector of the six planes was calculated out based on the selected three points on each plane, the features’ direction could be identified by comparing the two orientation vector parameters. The result is that CAM system can arrange the gear-box parts’ clamping position more conveniently after the features owned orientation planes are identified.