Abstract: According to the textural features of the guttate, myrmekitic, or threa dlike minerals and the occurrences of host tsumoites under optical and scann ing electronic microscopes, the micrographic textures of tsumoite and sulfides i n Dashuigou tellurium deposit are of two types. The first type shows metasomatic relicts of earlier pyrrhotites hosted in tsumoite, while the second type has t he `guest minerals or mineral mixtures' elongated in specific directions and d istributed metrically in tsumoite `hoster'. They suggest simultaneously two co ntradictory formation mechanisms in traditional meaning－metasomatism and exso lution. However, the mineral paragenesis and occurrence, similarity in chemical comp ositions by EPMA between the "guest minerals" and accompanying sulfides and tell urides of earlier stages, and contrast letween the 2nd texturetype and the ideal model of `exsolution' eliminate the possibility of `exsolution' and conclude a comprehensive metasomatism under varying environments by which these two types o f textures have been formed. From the first to the second type texture, metasoma tism of earlier pyrrhotite and chalcopyrite by Te, Bi rich fluids is intensified with the fluid/sulfides ratios increased and the environment stabilized. Weak a lteration in fluctuational environments would produce tsumoites with typical met asomatic features, whereas complete alteration in a stable environment could dis solve earlier pyrrhotites and/or chalcopyrites in the fluids and produce exsolut ion-like micrographic texture.