A leak proof needleless medical connector has a housing (10), an actuator (20), a resilient member (30) and an adapter (40). The housing (10) includes a valve tube (12). The valve tube (12) has a bottom annular blocking projection (121). The actuator (20) and the resilient member (30) are mounted in the housing (10) and the adapter (40) is mounted on a top of the housing (10). A bottom valve stem (34) is mounted in the valve tube (12) of the housing (10). A bottom end of the bottom valve stem (34) abuts the bottom annular blocking projection (121) of the valve tube (12) to close an open bottom of the valve tube (12). In use, a dosing unit (60) is screwed into the needleless medical connector. Thus, a flow channel is formed within the needleless medical connector and the dosing unit (60).
