Abstract: In this study, the causes of safety accident in construction site were derived and the risk of the causes of safety accidents was analyzed. First, the causes of safety accident at the construction site in Korea from 2016-2018 were analyzed to identify the causes of safety accident. The causes of safety accident were classified into 4M technique (Man, Machine, Media and Management) which is safety management technique. The risk of man, machine, media and management was analyzed using the eigenvector method and the risk of the causes of safety accident was analyzed. Using the risk of man, machine, media and management and the risk of the causes of safety accident, the final risk of the causes of safety accident was calculated. The risk of safety accident due to breaches of safety regulations or guidelines’, ‘inappropriate communication with worker’s, ‘inadequate construction method plans’, ‘lack of training and education of personnel’ and ‘inadequate recognition and evaluation of site hazards’ was analyzed to be high. All of the causes of safety accident with high-risk were analyzed as belonging to management. Therefore, safety management activities in terms of management are necessary to prevent safety accidents. In addition, by improving safety management activities for the causes of safety accident with high-risk, the effectiveness of safety management activities can be improved and safety accident can be prevented.