To improve a mounting method of a cross junction fitting with which an iron cage is assembled with no welding, and the cross junction fitting.

A cross junction fitting comprises an inner fastening cross junction fitting body with which a press-fixing part, a pair of inner fastening cross support parts and a pair of fastening screw parts are formed continuously, a mount washer and a nut. According to a mounting method of the cross junction fitting, an iron cage is assembled with no welding by cross-joining a hoop reinforcement or a reinforcing frame to a longitudinal main reinforcement, the press-fixing parts are locked to the upper longitudinal main reinforcement around a crossing portion and screwed and fastened to the lower longitudinal main reinforcement via the fastening screw parts and the mount washer. The mounting method includes, during fastening, curving the mount washer from side to side around the longitudinal main reinforcement within the range of from about 6° to about 9° for mounting and, during cross joining, deforming the front face of an outer fastening cross support part from about V shape to about U shape for mounting by screwing and fastening. An outer fastening cross junction fitting is approximately V-shaped correspondingly to the width of the longitudinal main reinforcement during cross joining and in the cross junction fitting, the inner fastening cross support parts are formed approximately as wide as the reinforcing frame or the hoop reinforcement.