PURPOSE : To build a vertical wall body at low cost without needing forms, by a method wherein columnar structures are driven in a ground at intervals in a manner that they are emerged from a ground surface, the structures are covered with forms made of cloth, and mortar is poured to build a wall body. CONSTITUTION : Columnar structures 1 are driven in a ground in a manner that they are emerged from a ground surface to form a row of the columnar structures 1. The row of the structures 1 are covered with forms 2 made of cloth, and the side of the forms 2 made of cloth is tightened against the colum nar structures 1 by means of a binding material 5 being a nylon rope.Concrete 6 is placed in the forms 2 made of cloth with the aid of a concrete pump, but reinforcing bars are arranged, where necessary, to complete a protection wall body. This enables building of a vertical wall body without needing a slope gradient, and permits effective utilization of an estate area.