This study deals with a cooperative route guidance for a ground mobile robot with visually assisted by an autonomous drone. The cooperation between the ground robot and drone is generated within a symbolic motion plannar using behavior tree. The drone observing the ground envrionment generates the occupancy grid map to find the passable routes. The map infromation is shared with the ground robot which also configures the occupancy grid map based on the its own ovservation, and both of the map is integrated to find the optimal route for the ground robot. Experimental results illustrate the feasibility of cooperative navigation strategy.