Mesozoic intermediate- acid intrusive rocks are widespread in the Tongling ore concentration area of Anhui Province and are closely related to polymetallic- copper mineralization. Although numerous studies have investigated the genesis of these intrusions, controversies remain. This study focuses on Tongguanshan and Dongguashan quartz diorite and Fenghuangshan and Hucun granodiorite to further explore their genetic mechanisms. We conducted a comprehensive geochemical analysis, including major and trace element compositions, Sr- Nd isotopic ratios, and zircon and apatite geochemistry. Integrating these data with previous research, we propose a refined model for the origin of these intrusive rocks. Our findings indicate that the Mesozoic intermediate- acid intrusive rocks share similar major and trace element compositions, classifying them as high- K calc- alkaline rocks with characteristics of both arc magmatic and adakitic- like rocks. They also exhibit enriched Sr- Nd isotopic compositions. These geochemical characteristics, coupled with petrological observations of mafic microgranular enclaves (MMEs) and antiband structures of amphibole and plagioclase, indicate that their parental magma originated from the mixing of mafic and felsic magmas. Our new analytical results provide further insights into the petrogenesis of these intrusions. Inherited zircon U- Pb ages predominantly cluster within two ranges: 1.0~0.8 Ga and 2.4~2.0 Ga. Corresponding εHf(t) values range from 20.5 to 5.1, indicating two- stage Hf model ages between 1.5 and 2.9 Ga. Zircon δ18O values fall between 5.93 ‰ and 8.85 ‰. Apatite geochemistry reveals high Cl contents (average 0.3%) with relatively high Cl/F ratios (0.052~0.244), high REE contents (1714×10-6~5903×10-6), and negative δEu values (0.26~0.68). Based on combined geochemical characteristics of whole rocks, zircon, and apatite, and considering regional geological tectonic evolution, we challenge existing views on the genesis of these intrusions and propose a new model. We suggest that the Mesozoic intermediate- acid intrusive rocks in the Tongling ore concentration area originated from a mixture of crust- derived and mantle- derived magmas. Specifically, this involved the mixing of enriched lithospheric mantle- derived magma with Neoproterozoic juvenile arc crustal- derived magma. A minor contribution from ancient crustal materials, dating back to the Paleo- Proterozoic to Meso- Proterozoic, was also incorporated during magma ascent. The enriched lithospheric mantle source magma was derived from the subducted oceanic crust or the fluid metasomatic overlying lithospheric mantle when the Cathaysia oceanic slab subducted beneath the Yangtze craton in the Neoproterozoic era, rather than the Mesozoic Paleo- Pacific slab subducting beneath the South China plate. The rollback of the Mesozoic Paleo- Pacific slab triggered the extension and thickening of the ancient orogenic belt, leading to lithospheric mantle thinning and melting.