PURPOSE: To provide a method for bonding an end of a dirrerent section molding having a common part which can not only simplify extremely labor for bonding the molding end but also can treat beautifully an end bonded part.

CONSTITUTION: When two synthetic resin moldings having a partially common end section part are bonded, the following processes are taken; a process wherein an end face to be bonded of each molding is melted by heating, a process wherein a common section pant of the end face to be bonded in a melted state of each molding is bonded and besides an outer periphery of the common section part is integrally welded while being controlled with a specific molding edge, and a process wherein a non-bonded part is worked by cutting in a specific form after the welding process.