Thin MoCN films were synthesized by a method of cathode sputtering of mosaic Mo-C targets by nitrogen ions at temperature of 800°C on substrates of the oxidized silicon. The temperature dependences of electrical resistance of the films in the range of 4.2–300°K were measured. Volt-ampere characteristics of the films and critical current density vs film thickness were obtained at a temperature of 4.2°K. The microstructure and film-depth chemical composition profiles of thin films were investigated by analytical techniques of the transmission electron microscopy (HRTEM, EELS) on a cross-section samples made by the focused ion beam (FIB). It was established that MoCN thin film at a thickness of 8 nm contained MoC and Mo5N6 layers. The high density of critical current in these films indicated prospects of their application in the field of cryogenic nanotechnologies.