A medical connector having a substantially cylindrical shape, a first upper end for receiving a male luer, and a second lower end, and including:a disc shaped valve member arranged at the first upper end and having an uppermost surface and a lowermost surface, a slit formed at a center portion thereof, an upper groove formed in a circumferential edge portion of the uppermost surface, and a lower groove formed in a circumferential edge portion of the lowermost surface；a housing with a pedestal for supporting the disc shaped valve member；a protrusion projecting upwardly from the pedestal and being arranged in the lower groove； andan annular ring member disposed on the circumferential edge portion of the uppermost surface, and having a claw portion projecting downwardly and being arranged in the upper groove on the uppermost surface of the valve member.
