Located in the central segment of the Jiangnan Orogen polymetallic metallogenic belt, the Lishan Pb-Zn-Cu deposit is a large deposit discovered in recent years. The biotite monzogranite and two-mica monzogranite are characterized by high-K calc-alkaline series. The biotite monzogranite is enriched in LILE of Rb, Th and K, and depleted in HFSE of Ba, Nb, Ta, Sr, P and Ti, with weak negative Eu anomaly, and belongs to normal S-type granite with a source rock of metagraywacke; whereas the two-mica monzogranite is enriched in LILE of Rb, Th, U and K, and depleted in HFSE of Ba, Nb, Sr, P and Ti, with significant negative Eu anomaly (greater than that of the biotite monzogranite), and belongs to fractionated S-type granite with source rocks of metapelite and minor metagreywacke. The biotite monzogranite has (87Sr/86Sr)i values of 0.7143 to 0.7159 and εNd(t) values of −9.4 to −8.5 with two-stage model ages of 1631 Ma to 1703 Ma; the two-mica monzogranite has (87Sr/86Sr)i values of 0.7156 to 0.7231 and εNd(t) values of −11.2 to −9.5 with two-stage model ages of 1696 Ma to 1834 Ma. These monzogranites were likely derived from partial melting of the Neoproterozoic Lengjiaxi Group metasedimentary rocks and experienced fractional crystallization. The biotites in both the biotite monzogranite and two mica monzogranite are ferrobiotites, however, have different crystallization temperatures and oxygen fugacities, i.e., the biotite in the biotite monzogranite has crystallization temperatures of 651 ℃ to 695 ℃, and the oxygen fugacity (ƒO2) of −18.9 to −16.9, whereas the biotite in the two-mica monzogranite has crystallization temperatures of 515 ℃ to 659 ℃, and the oxygen fugacity (O2) of −23.8 to −16.0. The low oxygen fugacity of the two intrusions may be responsible for their limited Cu metallogenic capacity. © 2023 Science Press. All rights reserved.