The present invention addresses the problem of providing a sliding-surface lubricating oil composition capable of inhibiting the propagation of microorganisms in a cutting oil tank. The aforementioned problem is solved by a sliding-surface lubricating oil composition containing: a base oil (A); and one or more types of amine compounds (B) selected from the group consisting of a primary amine (B1) and a secondary amine (B2), wherein the primary amine (B1) has 12 or more carbon atoms, and the secondary amine (B2) has at least one cyclic structure group.