Abstract: The Ladigongma granite is located in the Tongtian river tectono-magmatic belt of the Xijin Ulan - Jinsha river suture zone. According to the outcrop research, the rock types could be subdivided into 3 units: the Ladigongma granodiorite (T₃γδ), the Riariqu quartz diorite (T₃δo) and the Mianqie tonalite (T₃δi). All of the granites are formed in the Late Triassic. The major elements results show that the granites are rich in silicon, aluminum, alkalis and volatile components; the rare earth elements results show intense fractionation between LREE and HREE with significant LREE enrichment and weak negative of Eu and Ce; and the trace elements are characterized by Rb, Th and Ba enrichment, and Y, Yb and Cr depletion. All of these are the characteristics of I- and S-type peraluminous granite. They have the same geochemical characteristics as the calc-alkaline granite in volcanic arc. It is inferred that the subduction of Duocai—Dangjiang tectonic melange zone in Late Triassic may be responsible for the granites in the study area. The granites are the continental collision type granite and the tectonic setting is subduction-convergent environment.