To provide a joint component for a resin fuel tank, capable of attaining an excellent welding force and barrier capability against fuel in a welding portion with an opening portion outer periphery of the resin fuel tank, and a manufacturing method therefor.

This joint component for a resin fuel tank is constructed from a body member 1, and a roughly cylindrical welding member 2 which is coaxially intervened at a space to the outer periphery of the opening portion Ta of the resin fuel tank T. The welding member 2 is formed out of a structural body with a plurality of layers having a roughly cylindrical barrier core material layer 21 and a roughly cylindrical welding material layer 22 provided at the inner periphery and the outer periphery. The roughly cylindrical barrier core material layer 21 is constituted of alloy material in which modified HDPE is mixed in EVOH or PA, thus constituting the roughly cylindrical welding material layer 22 by the modified HDPE.