In order to track the extened object stably and precisely,firstly,all straight-line edge features in extended object between neighboring frames are extracted and every intersection of straight-line feature edge can be described by slopes,obliquities and intercepts of two straight lines,then the intersections are matched between neighboring frames by computing the Euclidean distance minimum of descriptors,finally the centroid of intersections is considered as the tracking position. Experimental results show that the method has an excellent performance in the object tracking. If the object does not transform greatly,the tracking method is more stable and more precise than ordinary template matching method.