The invention provides a vibration damping rubber bushing with a new structure, which can achieve a stable sealing performance between the axial end face used as inner cylinder fitting and the opposed face of a member connected by vibration damping manner without influence to the rotation-resistance function of the anti-slip projections formed on the axial end face of the inner cylinder fitting. The vibration damping rubber bushing (10) is used for mounting the axial end face (40) of the inner cylinder fitting (12) onto a member (24) connected by vibration damping manner by pressing, and comprises the combination of the following two structures: (i) a plurality of axially outward anti-slip projections (42) formed on the circumference of the axial end face (40) of the inner cylinder fitting (12) extended with ribbed shape in a diametrical direction on the axial end face (40); an annular water barrier projection (44) provided on a diametrical medial section of the axial end face (40) of the inner cylindrical member (12), projecting axially outwardly and extending circumferentially, with the anti-slip projections (42) being disposed to both radially inner side and radially outer side of the annular water barrier projection (44).