In this research, we have been developed a field robot with behavior-based autonomous moving for labor-saving of forest industry. We focused on a behavior-based architecture as typified by Subsamption Architecture. In this paper, we describe a behavior-based autonomous moving system with decision of a destination autonomously to make the robot travel in the work space. An individual tree will be treated as landmark in an environment, and these treated as a vertices will construct a polygon which represents an unreached region for the robot. The system will guide the robot to make the polygon is divided.