The study of sulphate reducing bacteria effects (Desulfovibrio genus) has been focused on decreasing of some trace element concentrations in recent sediments of Khorram Abad watershed. The bacterias are a group of anaerobic microorganisms that have evolutionary varieties and frequently found in recent soils and waters. Adaptation of isolated culture of these bacteria has been performed through five successive generations. The rate of lead and selenium consumption in new generations (the fourth and fifth generations) of these bacterias, compared to the primary generations, indicates a sudden increase, as a consequence of purity of new generations (particularly fifth generation) and their culture enrichment. Thus, cultures of new generation are more suitable for decreasing of element^'s pollution in streambed quaternary sediments of this region and promote the biogeochemical processes. Maximum and minimum absorption rates of metallic trace elements in sediment by Desulfovibrio bacteria refer to chromium and lead respectively. Chromium is very important for bacteria growth and transition of exponential growth phase to constant phase. Lead solubility is low in aqueous systems and has relatively high frequency in stream sediments because of its poor absorption by bacteria. Maximum rate of sediment^'s transition elements removed by aforementioned bacteria is vanadium. This element participates frequently as an organometal in hydrocarbon compounds and the bacterial metabolic ability for its consumption is relatively high. It is possible to use microbial technique to minimize the sediment pollution related to this element with respect to high concentration of vanadium in quaternary organic shale of final sites of the northwest channels of the area. The maximum concentration of toxic elements is related to silty/clayey deposits of drainage distal zones of study area and microbial activity of mentioned bacteria is highest with regard to lowering of energy in these environments.