[Technical Problem]An object is to provide a sliding system which can drastically reduce the friction coefficient on a sliding portion by means of a novel combination of a chromium nitride film and a lubricant oil.[Solution to Problem]The sliding system according to the present invention includes: a pair of sliding members having sliding surfaces that can relatively move while facing each other; and a lubricant oil that can be interposed between the sliding surfaces facing each other. At least one of the sliding surfaces is formed as a coating surface of a chromium nitride film, and the lubricant oil contains an oil-soluble molybdenum compound that has a chemical structure of a trinuclear of Mo. When the chromium nitride film as a whole is 100 at % (referred simply to as “%”), the chromium nitride film contains 40-65% of Cr and 35-55% of N, and the chromium nitride film has a relative surface area of 15-60% wherein the relative surface area is a surface area ratio of (111) plane to (200) plane obtained when analyzed using X-ray diffraction. The lubricant oil preferably contains 5-800 ppm of the oil-soluble molybdenum compound in a content mass of Mo to the lubricant oil as a whole.