Tavreh mercury prospect, located in the NW of Iran, is a listwaenitic alteration and mineralization system which has structural control and is restricted to shear zones. In this study, the primary geochemical halo was investigated to estimate the level of erosion of this mineralization based on the lithogeochemical data. The assessment of the relative position of the erosion level of a geochemical anomaly is usually accomplished by comparing the values of the vertical geochemical patterns with values of the same parameters that are known around the similar mineralization. We used zonation indices (As.Sb.Ag/Cu.Co.Ni) and (Sb.As/Pb.Zn) as geochemical indicators in the determination of the present level of the geochemical anomalies in Tavreh area. The average value of the Vz1 index was obtained as 1.98*10-4, which is higher than the middle part of the recognized listwaenitic-type mercury deposits and is lower than the upper part of the supra-ore halo. The average value of the Vz2 index is 3.76, also indicating a supra-ore geochemical halo. Values of Vz1 and Vz2 indices imply the presence of sub-cropping the main part of ore body in the Tavreh area. It is expected that the values of Vz1 and Vz2 will be gradually decreased with increasing depth.