To shorten a work term for the construction of bridge pier foundation in a river or the like by rationalizing the construction process so that the construction of pier pillars can be completed within a drought period of the year.

An enclosure 30 is erected around a pillar construction site 10. A vertical shaft 40 larger in section than a pillar 50 is excavated within an anchor 23 at the bottom of the pillar 50. Precast concrete structures 51 made of hollow tubes are piled up within the excavated shaft 40 to form a pillar 50. Accumulations 24 within the enclosure 30 is cleaned and removed, and concrete 60 is placed between the internal wall 42 of the shaft 40 and the external circumference of precast concrete structures 51 to unite the pillar 50 with the anchor 23.