In order to promote the development of safety science, the establishment of the science of safety relations was conducted based on the most popular phenomenons of safety relations in safety science research and accidents prevention. Depended upon the features of safety relations architecture, the definition of safety relations is proposed, and its connotation, types and characteristics are analyzed. Accordingly, the definition of science of safety relations is proposed, its basic subject issues and heoretical basis are analyzed. Meanwhile, six methods of safety relations representation such as object and ogical representation are extracted, and the branch disciplines system of science of safety relations is constructed with follow eleven aspects. The results show that the research of the science of safety relations has a profound theoretical basis and practical basis, and the science of safety relations has wide applying fields and developing prospects.