A visually classification method of scenarios using differential information between normal scenarios is presented. Behaviors of normal scenarios of similar purposes belonging to the same problem domain resemble each other. We derive the differential information, named differential scenario, from such normal scenarios and apply the differential scenario in order to classify scenarios. Our method will be illustrated with examples. This paper describes (1) a language for describing scenarios based on a case grammar of actions, (2) an introduction of the differential scenario, and (3) a method of visualizing scenario classification named Scenario Map using the differential scenario.