The present invention discloses one liquid type cyanate ester-epoxy composite resin composition comprised of (A) cyanate ester resin, (B) epoxy resin and (C) latent curing agent. The present one liquid type cyanate ester-epoxy composite resin composition is characterized in that the above (C) latent curing agent is comprised of a modified amine (a), which has one or more amino group having active hydrogen within a molecule, obtained by a reaction of a polyamine compound (a-1) with an epoxy compound (a-2), and a phenol resin (b), and that the above polyamine compound (a-1) is a polyether polyamine compound and/or the above epoxy compound (a-2) is a polyether polyepoxy compound.