To obtain a production method of an integrated body of a counter driven gear with parking lock gear not requiring cutting of tooth tip end face of a parking lock gear.

A rough lock tooth part 111, which has a tooth major diameter and tooth width slightly larger than a final product, is formed by hot forging, by sizing with cold forging the rough lock tooth part 111 to reduce the tooth major diameter and tooth width, plastic working is executed so that material flows toward a tooth tip end face. Coining is executed at the final stage of this sizing, an end face 103 of the rough lock tooth part 111 is strongly pressed, a material is sent to the angle part intersecting the end face and tooth tip to fill underfiel of angle part, thereby making a lock tooth part having no underfiel at the angle part.