Abstract: A hierarchical and step-by-step recognition method is presented with three differently structured guidelines. The drawings are first normalized by eliminating multiforms of representing graphic elements,extracting outlines from special graphic elements （such as solid line and polyline),establishing geometric relations between lines and arcs,and determining thresholds based on statistics. Recognized results of prior steps are inherited for further processing.Beams and walls are identically considered as beam segments to simplify the definition and recognition of slabs.Finally,special rules are worked out to differentiate two modes of arranging stiffening ribs.The presented method has been applied in the budgeting software—VHRecQS.