Most of rhenium ( Re) in the world is concentrated in molybdenite of porphyry deposits, but Re concentrations vary significantly on the scales of ore deposits, samples and even individual molybdenite. At present, the factors causing these variations are still unclear. This paper focused on the Fujiawu and Tongchang deposits at Dexing copper ore field. Distribution characteristics and enrichment mechanism of Re in molybdenite, by using EPMA, LA-ICP-MS, mapping and XRD, were systematically studied. The molybdenite, the main Re -bearing mineral at Dexing copper ore field, can be divided into two types, coarse -grained leaf-shaped molybdenite and fine-grained aggregate molybdenite. The results of LA-ICP-MS trace elements mapping showed that the distribution of Re in molybdenite is extremely uniform, the fine-grained aggregate molybdenite was more likely to have high value areas of Re. For molybdenite of the same form, the Tongchang deposit often has higher Re contents. For the same deposit, the later molybdenite generally has higher contents of Re than the earlier ones. The kink phenomenon was observed in some molybdenite, and the content of Re in the kink site is lower, suggesting that the late tectonic deformation may lead to the loss of Re. The results of XRD analysis showed that the samples of high Re-bearing and low Re -bearing molybdenite were all 2H polytypes in both the Fujiawu and the Tongchang deposits, which indicated that there was no obvious correlation between the Re contents of molybdenite and molybdenite polytypes. The temperature, salinity and pH were the dominant factors leading to the heterogeneous enrichment of rhenium in molybdenite in the Dexing copper ore field.