To provide an extra-banking concrete treating means for a cast-in- place pile that can solve the problem of disposal after the use of the treating means for reducing the diameter of a slime mixed part in placing concrete for the cast-in-place pile.

The treating means 11 provided with vertically piercing through- holes 13 to main reinforcements 2a are annularly arranged being fitted to the upper end parts of the main reinforcements 2a of a reinforcing cage 2 when constructing the cast-in-place pile, to reduce the diameter of the extra-banking part of the placed concrete to thereby facilitate the removal of the extra- banking part. Since the treating means 11 are formed using paper as material, no problem of industrial waste arises in scrapping or incineration.