To obtain a lubricant oil to be used in lubricating high-speed rotating machines or the like, capable of reducing the frictional resistance with bearings in a turbulent flow condition and intended to sustain the reducing effect.

This lubricating oil is obtained by incorporating a base oil with a self-organized polymer where a plurality of monomers each having a hydrogen-binding site selected from primary amino group (-NH2), secondary amino group (-NH), tertiary amino group (-N), carbonyl group (-C=O), carboxy group (-COOH), hydroxy group (-OH) and functional group containing sulfur atom or fluorine atom are bound together via hydrogen bonds.