To prevent the base of a steel pipe column from breaking/bending for a steel pipe column base structural body constituting a base of the steel pipe column to be erected.

The steel pipe column base structural body is constituted of the steel pipe column 1, a base plate 5 for supporting the steel pipe column 1 and having the required number of anchor mounting holes 6, vertical ribs 4 erecting to the base plate 5, providing at least four or more vertical ribs in the circumferential direction of the steel pipe column 1 and reinforcing the steel pipe column 1 and an exterior finishing pipe 10 rolled on the steel pipe column in the vicinity of at least the upper end of the vertical ribs 4.