Based on an analysis of dynamic conditions for migration and precipitation of gold grains in water system and their diffusion in soil,this paper has advanced a discriminant formula for surfacce ore potential of gold anomalies from 1:50000 stream sediment survey, recounted methods for estimating the highest gold grade ores within the anomalies,calculated the discriminant indices for Qinba area,and summed up index characteristics of ore-induced gold anomalies in 1:10000 soil survey,estimation formulae for orebody location as well as coefficients and constants of slope angles of various orders and grades.These formulae and methods are of considerable practical significance.