The Tanchong and Chenchong granitic stocks are situated in the northern margin of Xinxian batholith within the western Dabie orogen. They consist of monzogranite and granite porphyry, respectively. Elemental, whole- rock Sr- Nd and zircon U- Pb- Hf isotopic analyses have been carried out in this study, in order to understand their petrogenesis and tectonic significance. LA- ICP- MS zircon dating yields U- Pb ages of 133. 5±1. 1 Ma and 132. 9±1. 1 Ma for the Tanchong and Chenchong granites, respectively, indicating they formed in the early Cretaceous. These granites are characterized by high SiO2 of 69. 40% to 77. 82%, Al2O3 of 11. 72% to 15. 26%, a total alkali of Na2O+K2O=6. 40% to 8. 70% with K2O/Na2O>1 and A/CNK=1. 14 to 1. 66, and belong to the high- K calc- alkaline series. They are enriched in LREE with (La/Yb)N=22. 98 to 28. 64 and unapparent Eu anomaly, and depleted in Ba, Nb, Ta, P, Ti and Y. They have moderate ISr values (0. 707220 to 0. 707557) and negative εNd(t) values (-17. 7 to -18. 1), with two- stage Nd model ages of 2. 36 to 2. 40 Ga. Zircon εHf(t) values are negative (-21. 4 to -25. 8) with an calculated two- stage Hf model ages of 2. 24 to 2. 48 Ga. Their petrographic and geochemical data suggest that the Tanchong and Chenchong granites are fractionated I- type granites, which are derived from partial melting of ancient crust of the Yangtze Block. Their equilibrated residues are probably garnet- bearing. We infer that the magmas of Tanchong and Chenchong stocks were formed in a thickened continental setting. Combining regional synchronous magmatic rocks, we propose that tectonic collapse of the western Dabie orogen probably started at about 133 Ma, which is consistent with the eastern Dabie orogen.