Aimed at the high cost of cement which was used as a cementitious material of filling in chinese metal mines, through tests and investigation, it was confirmed that Red mud cementitious agent used as cementitious material of filling has many merits such as being high in early strength, stable in late strength, able to meet the reguirements of filling in mines, either in setting time or in strength indexes; further more, its major raw materials are industrial wastes and its price is only one thind of that of cement so that it has good social and economic benefits.