[Technical Problem] An object is to provide a sliding system which can achieve both the reduced friction and the enhanced wear resistance by means of a novel combination of a sliding film and a lubricant oil.[Solution to Problem] The sliding system of the present invention comprises: a pair of sliding members having sliding surfaces that can relatively move while facing each other; and a lubricant oil interposed between the sliding surfaces facing each other. At least one of the sliding surfaces comprises a coating surface of a crystalline chromium carbide film. The lubricant oil contains an oil-soluble molybdenum compound that has a chemical structure of a trinuclear of Mo. When the chromium carbide film as a whole is 100 at %, the chromium carbide film contains 40-75 at % of Cr. The chromium carbide film in contact with the lubricant oil containing a Mo-trinuclear appears to react with the Mo-trinuclear adsorbed during the sliding to generate a layered structural body (boundary film) similar to MoS2 on the surface, thereby developing a considerably low friction property.