To provide a hair ornament which has a neat appearance of an ornament body, has excellent assembling characteristics and productivity, and is capable of preventing falling off of an ornament part even if a shock caused by a clicking is affected, and also to provide its assembling method.

A three-pin body comprises a click piece which can be freely moved in two standstill states by elastically deforming; and an opposite piece capable of elastically deforming, which is fixed to an end of the click piece and extends so as to face the click piece, and is butted or separated against or from the click piece by an operation of the click piece. The fixed ornament body 30 is fitted to the end of the three-pin body. The hair ornament 1 is comprises the three-pin body and the fixed ornament body. The fixed ornament body 30 is fitted by using a tubular fixing boss 10 welded to a burr-like member protruded along a thickness direction of the three-pin body 2.