A computer vision system for robot is developed which can recognize a variety of two dimensional complex objects in gray level noisy scenes. the system is also capable of determining the position and orientation of the objects for robotlc manipulation. The hardware of the vision system is developed and a new edge tracking technique is also proposed. The linked edges are approximated to sample line drawing by split and merge algorithm. The system extracts many features from line drawing and constructs relational structure by the concave and convex hull of objects. In matching process, the input obhects are compared with the objects database which is formed by learning ability. Thelearning process is so simple that the system is very flexible. Several examples arc shown to demonstrate the usefulness of this system.