A new graph-based recognition method of undercut features from molded part is proposed. Attributes of node and edge in Face Adjacency Attribute Graph (FAAG) are extended to form Extended Face Adjacency Attribute Graph (EFAAG). Based on these theories, concave, convex and through undercut features are defined accordingly and sub-graphs of the undercut features are recognized from EFAAG of the molded part by graph matching. Feature orientation of each recognized undercut features is determined by visibility map and optimization parting direction is chosen from these feature orientations. The case study shows that the proposed method is available in recognizing the undercut features and improves the efficiency in undercut feature recognition.