To provide a locking implement high in versatility as a crime preventive implement, a connecting implement and a fixture.

This locking implement comprises a base body having a locking rod; a pressing type obstacle body pressed to face the base body and provided with right and left clamping type locking pieces engaged with an engaging head of the locking rod using the spring force of an internal spring; and a pressing key having a pair of engaging claw pieces inserted in a pressing manner into a key insertion opening formed by the facing end faces of the locking pieces, to uniformly push the right and left locking pieces open against the spring force of the internal spring when detaching the obstacle body united in a locked state to the base body through the locking rod.