A rotary compressor comprising: at least one cylinder installed in an inner space of a hermetic container, having a compression space for compressing a refrigerant, and provided with a vane chamber isolated within the inner space of the hermetic container; a plurality of bearings (120, 130) coupled to both upper and lower sides of the cylinder so as to cover the compression space of the cylinder and the vane chamber; at least one rolling piston configured to compress the refrigerant by being orbited in the compression space of the cylinder; at least one vane slidably coupled to the cylinder and configured to partition the compression space into a suction chamber and a discharge chamber in cooperation with the rolling piston, at least one thereof being supported by a refrigerant filled in the vane chamber of the cylinder; and a mode switching unit configured to vary an operation mode of the compressor by selectively supplying a refrigerant of suction pressure or a refrigerant of discharge pressure to the vane chamber of the cylinder, the cylinder is provided with a connection hole for allowing the vane chamber to be communicated with the mode switching unit by inserting a connection tube into the connection hole for allowing the connection of the connection pipe of the mode switching unit, the rotary compressor characterised in that the vane chamber of the cylinder is provided with a connecting protrusion protruded from an inner circumferential surface thereof so as to be stepped, and in that a curvature of an end of the connecting protrusion is smaller than a curvature of the inner circumferential surface of the vane chamber such that the refrigerant supplied into the vane chamber is concentrated toward the vane. at least one cylinder installed in an inner space of a hermetic container, having a compression space for compressing a refrigerant, and provided with a vane chamber isolated within the inner space of the hermetic container; a plurality of bearings (120, 130) coupled to both upper and lower sides of the cylinder so as to cover the compression space of the cylinder and the vane chamber; at least one rolling piston configured to compress the refrigerant by being orbited in the compression space of the cylinder; at least one vane slidably coupled to the cylinder and configured to partition the compression space into a suction chamber and a discharge chamber in cooperation with the rolling piston, at least one thereof being supported by a refrigerant filled in the vane chamber of the cylinder; and a mode switching unit configured to vary an operation mode of the compressor by selectively supplying a refrigerant of suction pressure or a refrigerant of discharge pressure to the vane chamber of the cylinder, the cylinder is provided with a connection hole for allowing the vane chamber to be communicated with the mode switching unit by inserting a connection tube into the connection hole for allowing the connection of the connection pipe of the mode switching unit, the rotary compressor characterised in that the vane chamber of the cylinder is provided with a connecting protrusion protruded from an inner circumferential surface thereof so as to be stepped, and in that a curvature of an end of the connecting protrusion is smaller than a curvature of the inner circumferential surface of the vane chamber such that the refrigerant supplied into the vane chamber is concentrated toward the vane.