Due to the progress of portable computing devices such as PDAs, cellular phones and small sized PCs, many personal navigation systems have been developed which navigate their users to display routes to given destinations. Those navigation systems mainly focus on the guidance for personal use. In this paper, we have developed a group navigation system, which provides facilities for (1) personally customizable route navigation to a given destination, (2) management of group movement and (3) rehearsal usage when we make the personally customized route navigation. In our system, using wireless ad-hoc communication a few leaders of a group can collect and distribute the information about its members' current positions and give each member a suitable suggestion when the user is losing his/her way. The personalized route navigation scenario (program) running on portable devices can be obtained automatically only by clicking intersections sequentially on a given map and giving pictures and comments. A rehearsal mode is also prepared when we make the personalized route navigation.