Post-collisional magmatism is one of the key objects for exploring the composition of lithosphere and retrieving the deep geodynamic processes. Recently, our research group identified a new set of Cenozoic adakitic intrusive rocks in the Reskam area, southeast Pamir. In this paper, we report zircon U-Pb ages, whole-rock major and trace elements, whole-rock Sr-Nd and zircon Lu-Hf isotope compositions of these adakitic rocks. Zircon LA-MC-ICPMS U-Pb dating results show that these magmatic rocks were emplaced at Miocene (12.0 ± 0.3 Ma). Geochemically, they have high SiO2 (72.14% ~ 74.35%) and high K2O (3.78% ~ 5.25%) contents, with low MgO (0.13% ~ 0.50%) and Mg# value (18 ~ 35). They exhibit high Sr (363-754 ppm), low Y (3.41-16.4 ppm) and Yb (0.327 ~ 0.903 ppm), thus high Sr/Y (27 ~ 188) and (La/Yb)N (18.95 ~ 210) ratios, in keeping with the typical adakites. In terms of isotopes, they have significantly enriched in situ zircon εHf(t) (-10.1 ~ -5.4) and whole-rock εNd(t) (-8.33 ~ -6.39) values. In combination of the data in this study and the published references, the Reskam Miocene adakitic rocks were most likely originated by partial melting of thickened lower crust as a result of India-Asian collision. We suggest that collapse of the local thickened lithosphere due to gravitational instability, and the upwelling of the asthenosphere caused partial melting of the thickened old lower crust, forming the Miocene adakitic magma.