The Hekanzi deposit is a medium-size porphyry molybdenum deposit in western Liaoning Province. Isotopic ages of the Hekanzi alkaline granite and its related Mo polymetallic deposit have been determined. The rock-forming age of the biotite-orthoclase granite is (235.3±1.0) Ma with MSWD value of 0.68. Re-Os isotopic data of six molybdenite separates define a correlation line corresponding to an age of (224.0±1.3) Ma with MSWD value of 0.72. The metallic minerals in the ore are pyrite, chalcopyrite, molybdenite, pyrrhotite, marcasite and a little scheetine. Gangue minerals are mainly calcite, fluorite, garnet, serpentine, peridotite, dolomite, feldspar, plagioclase and quartz. The NE-trending, NS-trending and NW-trending fault zones are widely distributed in the alkaline intrusive complex and its related molybdenum polymetallic deposit at Hekanzi.