Abstract: In order to display 3Dassembly guiding information on suitable screen area in a proper viewpoint,this paper proposes an adaptive information display method for assembly guiding.The method includes adaptive selection of display area and viewpoint.For adaptive selection of display area,firstly the display screen is divided into many grids.Then this paper calculates the screen coordinates for vertexes of bounding boxes of CAD features and judges whether the screen grids are occupied by the bounding boxes of CAD features.Lastly the maximum connected region is chosen to display 3D guiding information.For automatic viewpoint selection,a viewpoint perception metric operator,which takes both projection area and stereoscopic characters into account,is put forward. Both methods proposed in this paper use bounding boxes of CAD features as input data,so they are intelligent and universal.