PURPOSE: To provide a body mounting frame manufacturing method that can connect only by spot-welding easy from the viewpoint of work so as to be suitable for mass production, low in manufacturing cost and high in accuracy.

CONSTITUTION: A body mounting frame is built up by fixing mutual flanges 15 of structural angles 13, made of an aluminum alloy, by resistance spot- welding. The flanges 15 are formed integrally with a body 14 at the time of forming the structural angle 13 by extrusion. Or the structural angles are connected through node members. The node member is manufactured by forming a node member body by extrusion and then welding a side plate serving as a spot-welding flange, piercingly to the body by laser welding.