Dali quartz monzonite (porphyry) body lies at southern Dali Town of Tengxian County in Guangxi. Through discussing the regional tectonic evolution and exploring the basic properties, causes and tectonic environment of the rocks, the authors analyzed the favorable conditions of mineralization and inferred the porphyry copper-molybdenum mineralization age. The main favorable ore-forming conditions lie in the following three aspects: 1) I-type quartz monzonite (porphyry) is a good parent rock for mineralization; 2)the ore district has relatively high background values of Cu, Mo, Pb, Sn ore-forming elements; and 3) deep fault and #-shaped fault system of the study area constitute a favorable ore-controlling tectonic background.