Large-sized Cu-Au deposits are closely related to Late Mesozoic intrusive rocks in the Tongling area of Anhui Province. To discuss the potential of apatite as a petrogenetic-metallogenic indicator, the authors conducted a detailed in situ geochemical study of apatite from four representative intrusions (Jinkouling granodiorite, Tongguanshan and Dongguashan quartz monzodiorite, and Chaoshan pyroxene monzodiorite) in the Tongling area. The analyzed apatites of the Tongling intrusive rocks have high Sr/Y ratios (3.19 on average) and lower Y values, indicating that they are adakitic rocks. The apatite samples have F values ranging from 2.63% to 4.02%, and are defined as fluorapatites. The studied apatite samples have high REE content (825×10^-6~5 853×10^-6), moderate δEu values (0.37~0.88), high log f_O2 values (-12.3~-9.86), relatively high Cl content (mostly>0.2%) and Cl/F ratios, showing that the Tongling intrusive rocks might have been formed from mixed source of mantle-derived and crust-derived magmas in a high oxygen fugacity environment. The results indicate that the Cu-Au mineralization in the Tongling area may be closely related to the slab-derived Cl-enriched fluids, an oxidizing environment and a mantle-crust mixed source.