Abstract: Various landscapes are found in Tanzania.Bedrocks are well-exposed and streams are well-grained in most areas.This paper has ascertained the geochemical background of Tanzania, clarified the specific geological and geochemical significance of elements-rich area, by conducting national scale(1:1 000 000) stream sediment geochemical mapping.This work has collected 4258 samples in total.71 elements for each sample are analyzed by matched 13 analytic methods, including ICP-MS and XRF.The results show that the Au anomaly is distributed mainly in the greenstone belt of Lake Victoria, and there is a continuation of gold-rich terrain in the surrounding mobile belt.Medium and medium-high temperature metallogenic elements such as Ag, Cu, Pb, Zn, W, Sn, Mo, Nb and Ta anomalies are mainly distributed in the Kibara tin metallogenic belt, Malagarasi platform and volcanic rocks of East African Rift System(EARS).The anomalies of Ni, Co, Cr and V are mainly related to mafic-ultramafic rocks which are located in the Malagarasi platform, Ubendian Mobile Belt and volcanic rocks of EARS.This study delineates 31 gold geochemical blocks and 8 gold metallogenic prospective areas, and gold resource potential is preliminaries evaluated by geochemical block method.It provides favorable information for development of gold and other mineral exploration and fundamental research in Tanzania.