This study aims to reveal the preparedness behavior of SD Negeri 6 Mataram students from the knowledge of disasters that have been obtained. Preparedness is an important thing in reducing disaster risk. The research sample was the fifth grade students of SD Negeri 6 Mataram who had been given knowledge of disasters such as definitions, signs, impacts, risks and efforts to reduce, preparedness and procedures and tools for first aid to victims. The research objective was achieved by revealing the level of knowledge of disasters and disaster preparedness behavior in grade V SD Negeri 6 Mataram. This type of research is quantitative descriptive research. The results showed that the students' level of disaster knowledge was in the medium category. The students' preparedness behavior in facing disasters is in the high category. This data provides an indication that knowledge of disasters affects student preparedness behavior for disasters.