Abstract: A water tap cartridge to be mounted on the barrel of a compression-type faucet essentially consisting of an inlet portion communicating with a water supply pipe, an outlet portion forming a tap hole, a horizontal dowel seat portion horizontally extending and forming a partitioning wall between said inlet portion and outlet portion and a cylindrical rise-up portion extending vertically above said dowel seat portion, said rise-up portion being provided with a packing retaining thread on its top exterior surface, which comprises a cylinder having a flange portion, said cylinder being such that its lower end seats on said seat portion and its flange abutts the top end of said cylindrical rise-up portion when the cartridge is mounted on the faucet barrel, a cap nut adapted to be screwed onto said packing retaining thread with said flange being interposed therebetween so as to fix said cartridge rigidly with respect to the barrel, said cylinder having an orifice which is brought into communication with said outlet