Mineral deposits characterized by outcropping hard-rock mineralization are well explored and currently being depleted. Consequently, mineral exploration is increasingly focusing on areas where thick layers of overburden conceal potential mineralization. Critical to the development of successful predictive exploration techniques in these areas is an understanding of processes that lead to trace element dispersion and re-concentration, and thus mediate the formation of surface and near surface expression of buried mineralization. To generate an understanding of the relationship between microorganisms, their geochemical environment and processes relevant to mineral exploration, “exploration geomicrobiology” has emerged as a new area of research. The primary purpose of this study was to survey the possible relationship between soil bacterial populations with mineral deposit occurrence underground in order to find a biogeochemical index in mineral exploration. Irankouh Pb-Zn mining area was selected as the sampling site. In this study firstly, modeling of small Tapehsorkh mineralization was completed by employing core drills results and then soil sampling transects were selected. All soil samples were collected from 10-30 cm depth to avoid surface contamination and rock samples from non-weathered rock. The samples were divided into two parts for chemical and microbial analyses. Geochemical samples were prepared and total metal analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-OES). Bacterial count of the total population, microbial respiration and soil chemical characteristics such as pH and electrical conductivity were measured in all samples. The results of the counting of soil bacteria were showed a ltr"