In sulphide-bearing mine tailings, hardpan formation is the weathering process of reactive minerals to form the precipitation of secondary minerals and cementation of tailing particles. This weathering process is directly stimulated by mineral-microbe interactions (such as Fe/S-oxidizers) and associated mineralogical and geochemical changes in the tailings. The present study aimed to characterize the microstructure and associated microbes within the continuum of oxidized hardpan and the transition zone of uncemented tailings by means of SEM and FE-SEM/EDS. Microbial DNA in the hardpan was extracted by using cell disruption with concentrated sucrose, which was for phylogenetic analysis of 16s DNA within illumina MiSeq pyrosequencing platform. It was found that gypsum and Fe-Si evaporites were the dominant bonding agents throughout hardpan profile, while gypsum evaporite was more likely to be presented in surface hardpan (0-10 cm) in compared to Fe-Si evaporite in bottom hardpan (25-40 cm). In addition, the source of gypsum evaporite might be come from (1): liberation from crystalline gypsum minerals; (2) the weathering products of amorphous phases (gels) through carbonate mineral (dolomite) surface dissolution. Accordingly, the Fe-Si evaporite might be formed from the association between crystalline Fe minerals (pyrite or Fe oxides) and amorphous silicate clays. As for the 16s DNA microbial community analysis, it was indicated that the higher abundance of Fe&S oxidizers were presented in the bottom hardpan profile (25-40cm) but low in surface layers (0-10 cm) and unweathered tailings (below 40cm). The present results confirmed the fundamental knowledge of precipitating evaporites and microbial community related to hardpan formation from sulphide-bearing mine tailings in semi-arid climate, which will be beneficial to mine site rehabilitation through engineered pedogenesis pathway.