Primary dispersion halos from a impregnation type Nb-Ta granite in Hunan have been dealt with in this paper. Using Nb, Ta, W, Sn, Be, Li, Rb, Cs as indicator elements, the author has successfully detected ore anomalies and then delineated ore bodies. As evolution of elements finds expression in ore body associations, abundance of minerals and variations in typomorphic minerals, mineralogical features such as mineral halos and characters of typomorphic minerals seem likely to furnish their own information for ore detection. Vertical zoning of primary halos suggests that, in locating ore bodies, Li, Rb, Cs, Bi, Aa may be used as distant indicator elements whereas Nb, Ta, Be serve well as near-ore indicator elements.