A rotary compressor, comprising: a rotational shaft coupled to a drive motor to transfer a rotational force and having a central passage formed therein along a longitudinal direction thereof; an eccentric portion provided eccentrically from the rotational shaft ; a cylinder through which the rotational shaft passes, the cylinder being configured to form a compression chamber in which a refrigerant can be accommodated at a central portion thereof; a roller having an inner circumferential surface configured to be in close contact with an outer circumferential surface of the eccentric portion , the roller being configured to roll in a state where an outer circumferential surface thereof is in contact with an inner circumferential surface of the cylinder as the rotational shaft rotates, and compresses a refrigerant; a vane inserted into the cylinder , the vane being configured to protrude from the inner circumferential surface of the cylinder when backpressure is applied to the vane to be in contact with the outer circumferential surface of the roller , and configured to partition the compression chamber into a plurality of chambers; and at least one, preferably a plurality of oil supply grooves formed on the outer circumferential surface of the eccentric portion ; and an oil supply passage that communicates the central passage with the oil supply groove ; characterised in that an angle (a) between a groove surface disposed rearward with respect to a rotational direction (R) of the eccentric portion and the outer circumferential surface of the eccentric portion is formed larger than an angle (b) between a groove surface disposed forward with respect to the rotational direction (R) of the eccentric portion and the outer circumferential surface of the eccentric portion , in the oil supply groove . a rotational shaft coupled to a drive motor to transfer a rotational force and having a central passage formed therein along a longitudinal direction thereof; an eccentric portion provided eccentrically from the rotational shaft ; a cylinder through which the rotational shaft passes, the cylinder being configured to form a compression chamber in which a refrigerant can be accommodated at a central portion thereof; a roller having an inner circumferential surface configured to be in close contact with an outer circumferential surface of the eccentric portion , the roller being configured to roll in a state where an outer circumferential surface thereof is in contact with an inner circumferential surface of the cylinder as the rotational shaft rotates, and compresses a refrigerant; a vane inserted into the cylinder , the vane being configured to protrude from the inner circumferential surface of the cylinder when backpressure is applied to the vane to be in contact with the outer circumferential surface of the roller , and configured to partition the compression chamber into a plurality of chambers; and at least one, preferably a plurality of oil supply grooves formed on the outer circumferential surface of the eccentric portion ; and an oil supply passage that communicates the central passage with the oil supply groove ; characterised in that an angle (a) between a groove surface disposed rearward with respect to a rotational direction (R) of the eccentric portion and the outer circumferential surface of the eccentric portion is formed larger than an angle (b) between a groove surface disposed forward with respect to the rotational direction (R) of the eccentric portion and the outer circumferential surface of the eccentric portion , in the oil supply groove . <EOS>