The geology and mineralogy of the Hejiangkou deposit and conducted Re-Os isotopic dating on molybdenite from the Hejiangkou deposit were systematically studied. The dating results provided new evidence for the mineralization that occurred during the Indosinian (225±3.6 Ma). By combining the rock-forming ages and mineralization ages obtained by both previous researches, the Xitian area experienced multi-periods mineralizations. Moreover, the metallogenetic tectonic settings of different mineralizations were also discussed. The results show that period I is the Indosinian mineralization period that involves mixing between both crust-derived and mantle-derived ore-forming materials. The period of mineralization took place under the compressional tectonic regime and featured by the weak mineralization. Period Ⅱ is the early Yanshanian mineralization that represents the main mineralization period of the area and is related to a large influx of mantle-derived materials under an extensional regime. Period Ⅲ is the late Yanshanian porphyry-skarn type mineralization that is related to the emplacement of granite-porphyry veins and is a recently discovered type in the Xitian orefield. The porphyry-skarn type mineralization also becomes the target of the future ore-prospecting.%对合江口矿的矿床地质特征，特别是岩相学和矿相学特征进行系统研究，并对该矿床中的辉钼矿进行Re-Os同位素测年，获得印支期(225±3.6 Ma)成岩成矿作用的地质和年代学证据；结合以往的成岩成矿时代资料，认为锡田地区存在多期成矿事件，并讨论成矿动力学演化特征。结果表明：合江口矿床的第Ⅰ期成矿事件发生在印支期，成矿物质来源为壳幔混合源，发生于挤压大地构造背景中，矿化较弱；第Ⅱ期为燕山早期，在拉张的构造背景下，幔源物质大规模参与成矿，是本区的主成矿期；第Ⅲ期为燕山晚期，是与花岗斑岩脉侵入相关的斑岩−矽卡岩型矿体的成矿期，该期形成的矿体为锡田矿田内新发现类型，也是下一步的找矿方向之一。
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