The Jiusangou ore deposit in Yanbian area of Jilin Province is a typical epithermal-mesothermal gold deposit. In this study, detailed studies were carried out by means of zircon LA-ICP-MS U-Pb dating of the host rock of the Jiusangou gold deposit, i.e., altered diorite porphyrite. The analysis yielded U-Pb concordant ages of single zircons from 103 Ma to 116 Ma, with weighted mean age being 109.3±2.1 Ma(MSWD=7.0,n=18), which can be regarded as the rock-forming age of diorite porphyrite. The ages obtained can be subdivided into two groups: 112～116 Ma(Mean=113.1±1.1 Ma, n=9,MSWD=0.55, reliability=0.82)and 103～110 Ma(Mean=105.8±1.8 Ma, n=9, MSWD=2.2, reliability=0.022). According to the age of zircons and the crystal form of zircons or CL image characteristics, it is preliminarily determined that the former group of ages should represent the crystallization age of the main body of the diorite porphyrite, whereas the latter group of ages should represent the end of the magmatic evolution. According to regional metallogenic regularity and previ-ous achievements, the authors hold that the thermal event of the gold mineralization took place before 106 Ma. The results of this study suggest that the metallogenic environment was the subduction and extinction of Izanaqi plate towards the ancient Asian continent in late Early Cretaceous and the conversion process of slip or extension structures in eastern China continental margin during the Late Yanshanian orogenic movement.