Line structure is the most basic structure for a simple polyhedron. In stereo vision

the line structure extraction from a perspective view of a simple polyhedron is the key step for later corresponding problem

recognition and understanding. This paper presents a new method which is based on edge structure information to obtain a line structure of a polyhedron. Using the two-step edge following and edge mending this method finds feature vertices and their structural relations and creates two-dimensional feature description of a polyhedron. It can give a satisfactory result even under the situation of smaller image size of an object.