There is disclosed a heat treating oil composition which comprises (A) at least one base oil selected from a mineral oil and a synthetic oil each having a sulfur content of not more than 300 ppm and (B) at least one member selected from alkaline earth metal salts of salicylic acid. There is also disclosed a heat treating oil composition which comprises (I) a base oil having a sulfur content of 3 to 1000 ppm consisting of said (A) component and (C) at lease one member selected from a sulfur and a sulfur compound, along with (II) various additives for quenching.This heat treating oil composition is suitable for quenching under the condition of a high oil temperature and capable of obtaining a treated metal excellent in brightness and having a minimized distortion.