Abstract: An assembling method of a fuel injection valve for fuel injection into an internal combustion engine, the fuel injection valve including a cylindrical valve body having a fuel passage therein and a through-hole made in a direction of the axis thereof and a cylindrical nozzle coupled to the valve body and having a plurality of injection holes for dividing the fuel exited from the through-hole into a plurality of parts and for injecting the divided fuel parts into the engine. The assembling method comprises the steps of coupling the nozzle to the valve body, rotating the valve body relative to the nozzle, and stopping the rotation of the valve body when the through-hole takes a desirable position relative to the injection holes and fixedly securing the nozzle to the valve body.