The invention provides a lubricating oil composition comprising: a lubricating base oil having a kinematic viscosity at 100° C. of 1-10 mm2/s, a % Cp of 70 or greater and a % CA of not greater than 2; a first viscosity index improver of 0.01-10% by mass, based on the total weight of the composition, wherein the first viscosity index improver is a poly(meth)acrylate having a weight-average molecular weight of not greater than 100,000; and a second viscosity index improver of 0.01-50% by mass, based on the total weight of the composition, wherein the second viscosity index improver is a polymer having a weight-average molecular weight of 100,000 or greater and containing a structural unit represented by the following formula (1) in a proportion of 0.5-70 mol %, the composition having a kinematic viscosity at 100° C. of 4-12 mm2/s and a viscosity index of 140-300. wherein R1 represents hydrogen or a methyl group and R2 represents a C16 or greater straight-chain or branched hydrocarbon, or an oxygen- and/or nitrogen-containing C16 or greater straight-chain or branched organic group.