This invention relates to an oil-extended natural rubber capable of improving a tensile strength and a wear resistance of a rubber composition, and more particularly to an oil-extended natural rubber formed by adding an emulsified extension oil to a natural rubber latex and further coagulating and drying them. An amount of the extension oil added is preferable to be within a range of 5-80% by mass based on a rubber component in the natural rubber latex and the oil-extended natural rubber is preferable to have a weight average molecular weight as converted to polystyrene of a rubber component of not less than 1,500,000.