Abstract: The channeling dip asymmetry of <110> axis in the orystals with zincblende structure has been investigated and interpreted, qualitatively, as a result of the asymmetric arrangment of the As and Ga atomic rows on the plane perpendicular to <110> axis. Based on this experimental phenomenon, a new technique has been developed for lattice location of impurity atoms in ZnS-type crystals. The superiorities of this new technique over the conventional channeling technique for lattice location of impurity atoms have been evaluated. The hot-implanted impunity of group-Ⅳ element Sn in GaAs crystal has been identified on Ga substitutional site by this new technique.