Yuanpanbei Pb-Zn-Sn polymetallic deposit, located in Lianhuashan Fault, Eastern Guangdong Province, discovered in recent years, is genetically related to the monzonitic granite. In this paper, zircon U-Pb geochronology, geochemistry, and Lu-Hf isotopes of the monzonitic granite are conducted for the first time. Zircon LA-ICP-MS dating of monzonitic granite yields concordant ages of 151.8±1.5 Ma, which demonstrated that the monzonitic granite is formed in Late Jurassic. Petrographic and geochemical data indicate that monzonitic granite is characterized by weak peraluminous and belongs to the high-K calc-alkaline series, enriched in Rb, Th, U, K, Pb, and depleted in Ba, Sr, Ti, P, Nb, Ta with strong negative anomaly of Eu. Meanwhile，the monzonitic granite shows highly fractionated I-type affinity. The highly fractionated nature, abundant ore-forming metals, low fO2, and close spatial relationship with ore bodies indicate that the monzonitic granite is genetically related to mineralization in this area. The monzonitic granite has relatively high initial Sr isotopes (0.708865 to 0.708918) and relatively low εNd(t) (-6.72 to -7.25) and εHf(t) values (-15.52 to -5.05), with high tDM2 ages of εNd(t) (1568Ma) and εHf(t) (1343~1615 Ma), indicating that the source region of the Yuanpanbei monzonitic granite is most likely from the partial melting of the Mesoproterozoic ancient crustal rocks, which is possibly added by a few mantle material. Based on the results of geochemistry and geochronology, combined with the regional tectonic evolution, the monzonitic granite and tin polymetallic mineralization of the Yuanpanbei deposit were generated in an extensional tectonic setting triggered by the“slab foundering”of Paleo-Pacific plate.