PURPOSE: To easily and safely construct a large-scale cast-in-place pile surely having a desired strength.

CONSTITUTION: In a reinforcing member which can form a reinforcing cylinder 3 of a shape matching the shape of a cast-in-place pile 1 to be constructed by mutually connecting plural reinforcing members 10 in the circumferential direction, a female joint 21 and a male joint 25 which are extended in the vertical direction, are provided on the circumferential end parts 12b, 13b, of a reinforcing main body 15 divided in the circumferential direction. The male joint is engaged with the female joint of an another reinforcing member adjacent in the circumferential direction to form a filling space 30 extended in the vertical direction, and mortar 35 is injected into the filling space.