On March 11, 2011, Japan was hit by the Great East Japan Earthquake that caused massive tsunami along the shore of Tohoku to Kanto region and brought serious damage. More than 15,000 people were killed. Since the delay of evacuation had caused many victims, importance of the behavior studies in field of disaster prevention measurement has been recognized. To understand how coastal residents made decision and how they behaved at urgent situation become important because this knowledge will aid in the reconsideration of effective announcement in case of emergency and disaster education. Right after the earthquake, meteorological agency gave a large-scale tsunami warning including the coast area of Onjuku town, Chiba prefecture where the local government also issued an evacuation counsel to coastal residents. In this study, we distributed to all households in the coastal area of Onjuku town, totally 2,272 questionnaire forms. We asked to respond only who were in the town at the time of the earthquake. The questionnaire asked about their behavior in the form of flowchart and mapping with which we can identify where they were at the time of the earthquake and trace how they behaved after that as well as the reason of their choice such as knowledge and information used. With these, we aim to clarify the influential factors on their decision-making and path choice. From the data, 451 responses (collection rate: 19.8%), we analyzed residents' behavioral patterns. As a result, respondents acquired information from various source, while the degree of influence on decision-making varied with what type of information and how they received. Behavioral patterns are different according to the location and situation at the time of earthquake. At the same time, we found some risky behaviors made by the residents; some people came back to the home near the sea and others went to the seaside to watch tsunami.