Abstract: The constituent attribute configuration of DIG is an important and hard work in converting DIG data to GIS data，with the house attribute configuration being the principal part.Based on the spatial relation between a house polygon and its attributes and through the study and analysis of the available algorithms for judging a point in or outside the polygon，the ray method was adopted as the basic algorithm which was exceptionally treated.The automatic setting of the house attributes in DIG was realized by using this algorithm and a series of tests were also made on this algorithm.The algorithm was proven to be stable and reliable.

Key words: CAD, DIG, Automatic setting of attributes