Abstract: At present, the research on 40Ar/39Ar dating of supergene minerals in the arid zone of China is rarely conducted due to the complexity of the geochronology of weathering minerals. This paper introduces the experimental procedure of 40Ar/39Ar dating of supergene jarosite mineral composed mainly of systematic sampling, mineral identification and careful selection. With a variety of testing methods (XRD, SEM, EMPA), pure minerals can be obtained, and in combination with 40Ar/39Ar step heating analysis, reliable weathering ages can be acquired.