A rotor of an AC generator for vehicle according to the invention in which a conductor is wound around a spool in multi-rows and multi-layers is characterized in that at least gaps between the conductors at the deep portion out of the gaps between the conductors from the innermost layer to the outmost layer are filled evenly with resin forming resin layers A manufacturing method of a rotor of and AC generator for vehicle according to the invention includes the steps of applying a fluid resin material to a conductor immediately before the conductor is wound on a spool., and heating the entire structure to cause the resin to be heat-cured after the conductor to which the fluid resin material has been applied is wound around the spool in multi-rows and multi-layers.