Abstract: In order to study the characteristics of ore-controlling fault activities and ore-controlling laws in uranium mines to guide mineral exploration in northern Guangdong Province,the Nanxiong Fault Belt in the northern Margin of the Nanxiong Basin is taken as the research object,and the characteristics of the Nanxiong Fault Belt activities and the prospecting regularity of uranium mines have been discussed through researches on field geological sections,LA-ICP-MS zircon U-Pb chronology and characteristics of microstructural deformation. The research results show that the features on tectonic deformation of the Nanxiong Fault Belt in Triassic are mainly ductile deformation,and the post-magmatic hydrothermal quartz veins and felsic dikes in the Late Triassic cut through granitic mylonite and mylonite granite. Their weighted average ages of zircon U-Pb isotopic analysis are respectively (230. 2±1. 7) Ma,(228. 9±5. 8) Ma and (210. 0±2. 1) Ma. The microstructural characteristics of granitic mylonite and mylonite granite in the Nanxiong Fault Belt have show typical ductile deformation phenomenons with "S-C" fabric, elongation and dynamic recrystallization of quartz,"σ" type rotational fragmentation of quartz and book oblique structure of plagioclase feldspar. These characteristics of microstructural movement mainly present left-row shear in the direction of ductile deformation. In Triassic,two stages of elevated-temperature deformation and medium-low temperature deformation have been revealed. It is considered that these areas of 210 Ma ductile deformation in Nanxiong Fault Belt do not have the conditions of oreforming mechanism of critical transformation for precipitation of uranium mines. These is a inferential conclusion that the areas,in which the granites experienced strong ductile deformation in 125~120 Ma and 110~105 Ma,regional extensional movement of the same period and had been accompanied by intrusion of mafic dykes and uranium mineralization,can become metallogenic prospective areas of uranium mineralization or depositing uranium mines. This analysis results provide new ideas about appraisement of uranium mines and feasible prospecting for further improving the uranium resources in the integrated exploration area of southern Zhuguang Mountain.