A medical connector of improved configuration. Annular grooves are formed in both inner and outer surfaces of an outer peripheral portion of an elastic valve element to form an annular constricted section. An outer peripheral side from the constricted section is made to serve as an annular fixation section. A valve receiving seat is formed at an inner peripheral edge of an aperture portion in a housing, and an annular ring is fixed to the aperture portion to sandwich and support the annular fixation section between the valve receiving seat and the annular ring. Engaging projections formed on mutually facing surfaces of the valve receiving seat and the annular ring are engaged with the annular grooves, and either the engaging projection and/or the engaging projection is divided in a circumferential direction to have a plurality of projection-divisions.
