To obtain a lubricating oil composition having a long fatigue life, low temperature viscosity characteristics and oxidation stability even having a low viscosity, especially suitable for the transmissions such as an automatic transmission, a stepless transmission, a manual transmission, a final drive.

This lubricating oil composition for the transmissions is characterized by containing (A) lubricating base oil adjusted to have 1.5-6 mm2/s dynamic viscosity at 100°C and (B) 0.1-15 mass% poly(meth)acrylate-based additive without substantially containing a poly(meth)acrylate having ≥20C side chain, wherein, the (A) component consists of (A1) 70-97 mass% 1 kind or ≥2 kinds selected from lubricating base oils having 1.5-<7 mm2/s dynamic viscosity at 100°C and (A2) 3-30 mass% 1 kind or ≥2 kinds selected from lubricating base oils having 7-50 mm2/s dynamic viscosity at 100°C based on the total amount of the base oils, and having 3-8 mm2/s dynamic viscosity at 100°C and 95-200 viscosity index of the composition.