Granites can be divided into five types on the basis of their Sr and Yb content: high-Sr and low-Yb adakitic-type; low-Sr and Yb Himalaya-type; low-Sr and high-Yb Zhemin-type; very low-Sr and high-Yb Nanling-type and high-Sr and Yb Guangxi-type. Guangxi-type granites are exposed less in field and mainly composed of granodiorite, hornblende biotite granite, monzonitic granite and quartz syenite. Guangxi-type granites have low SiO₂, and are characterized by rich Al, Fe, K and P, belonging to shoshonite or high-K calc-alkaline series. Magma with high Sr and Yb content indicates lack of plagioclase and garnet in the residual phase. That means Guangxi-type granites are mainly composed of amphibolite plus/minus pyroxene, belonging to ultramafic rocks. Therefore, the condition for the formation of Guangxi-type granites was tough and needed high temperature at least. Guangxi-type granites are located in a narrow area in the phase diagram, above the plagioclase vanishing line, under the garnet appearing line and before the amphibolite disappearing line. Guangxi-type granites were formed under the pressure of about <1.0 GPa and at the temperature of >900℃ at least. These characteristics show that Guangxi-type granites were formed at the normal or thinning thickness of the crust with high temperature.