A lot of porphyry deposits, related to potassic intrusions closely, occur in the Jinsha-Ailaoshan metallogenic belt, western Yunnan. Liuhe orthophyre is barren magmatic rock and is located at the center of the belt. Based on petrography, the authors studied mineral characteristics of biotite, amphibole and zircon in Liuhe orthophyre, and investigated mineral temperature-pressure condition, magmatic oxidation state and water content. Depending on geochemical data and previous studies, the authors discussed the constraining condition for mineraliza-tion of potassic intrusions. Biotite has high MgO (12.98%~14.83%), CaO (14.18%~16.52%) content, with Fe²⁺/(Mg+Fe²⁺) ratios being 0.29~0.31. Mineral thermobarometric calculations show that crystallization temperatures of biotite are 615~669℃ under the pressure of 103~165 MPa and at the depth of 3~5 km (4.2 km on average). Amphibole consists dominantly of endenite and pargasite. Crystallization temperatures of amphibole are 817~843℃ under the pressure of 158~191 MPa and at the depth of 5~6 km (5.9 km on average). Oxygen fugacities (△FMQ) of magmas, constrained by chemical composition of amphibole, are +1.12~+1.27. Crystallization temperatures of magmatic zircons are 687~1 098℃ and Ce⁴⁺/Ce³⁺ ratios are 11.18~54.78 (Ce⁴⁺/Ce³⁺<50 on average), δEu=0.14~0.81 (δEu<1). Liuhe orthophyre has δEu ratios of 0.97~1.00, and whole-rock Dy/Yb ratios have negative relation and La/Yb ratios have positive relation with SiO₂ values, respectively. In addition, amphibole occurs as phenocrysts. These features indicate that a lot of amphibole crystallized at the early stage whereas crystallization of plagioclase was suppressed. The authors hold that Liuhe orthophyre had low oxygen fugacity and high H₂O content. Compared with mineral characteristics of fertile magmas of porphyry deposits, Liuhe orthophyre has no potential to form porphyry deposits.