Abstract
CSG has been rapidly developed as the new materials in the civil engineering field in the recent years. It was originally used as the materials for the temporary facilities, but is going to be used as the materials for the permanent facilities. CSG has the properties varying in a wide range because of its production process. So, it is the fundamental issue to clarify the magnitude of the material safety factor, in order to assure the safety of the CSG structures. This paper discusses the magnitude of material safety factor of CSG from the view of statistics and probability.