As the area of port for ships to stop, the recognition of jetty location is of great importance to the extraction of port. With the jetty distributing characteristics, a novel method for port detection is proposed. Firstly, improved regional growing method is used to acquire the binary image of land and water on the basis of image pretreatment. Then, the contour line is obtained through the edge tracking method. The jetty characteristics are extracted on the foundation of the contour line's slope. The target characteristic points of jetty are selected utilizing the prior knowledge of jetty. Finally, the ports are recognized. Experimental results indicate that the port contour gotten by the proposed method is more accurate than the existing methods.