Mobile computing research evolves constantly and quickly.  New mobile devices, technologies, methods, or applications are introduced every day.  One of the mobile applications, location-based services (LBS), has attracted great attention recently.  This research proposes location-based research, which uses location information to find route anomalies, a common problem of daily life.  For example, an alert should be generated when a pupil does not follow his/her regular route to school.  Different kinds of route anomalies are discussed and various methods for detecting the anomalies are proposed in this paper.  The proposed method based on a linear route representation finds the matched routes from a set of stored routes as the current route is entered location by location.  An alert is generated when no matched routes exist.  Preliminary experimental results show the proposed methods are effective and easy-to-use.