It is not difficult for residents, for the most cases, to know the knowledge of disaster prevention, while it is quite difficult for them to take appropriate evacuation behavior. For example, it is easy to know why flooded underpasses should not be gone through by cars. It is just because cars would be submerged and got stuck on the way. However, people sometimes fail to apply such knowledge to take an appropriate action, due to the so-called knowledge-to-action gap. In the present study, a preliminary investiga- tion and two experiments were conducted. The purpose of the investigation is to clarify the kinds of unsafe evacuation behavior with reference to newspaper articles on flood disaster over the past 15 years. The two experiments are to examine if the knowledge-to- action gap can be confirmed by means of paper-and-pencil tests consisting of knowledge and intention tasks. Preliminary investigation revealed ten kinds of unsafe evacuation behaviors in flood disaster. Experiments 1 and 2 indicated that participants take unsafe evacuation behaviors even though they have appropriate knowledge. In addition, the experiment 2 indicated that they perceived danger in unsafe evacuation behaviors and flood disaster situation.These results demonstrate an aspect of unsafe evacuation be- havior, and the importance of disaster prevention education, which has to be carefully designed to bridge the gap between knowledge and action for disaster prevention.