A side home-position device for a vehicle body assembly system for various vehicle types is disclosed, which can be used to return a common use side jig that controls a side panel to a working position of a main buck process. The device includes a post frame that is disposed in a vertical direction corresponding to the working position, a moving member that is movably disposed at the post frame in a width direction of a vehicle body and substantially supports the common use side jig, a main control unit in connection with the moving member and which returns the common use side jig to an original position, a clamper disposed on the moving member which clamps a matching portion of the common use side jig for the moving member, and an operating portion disposed at the post frame and which moves the moving member in a width direction of the vehicle body.