The gold and Pb—Zn—Ag ore deposits in the Qingchengzi ore concentration area in eastern Liaoning Province are strictly controlled by layer- parallel or layer- subparallel faults near the silicon—calcium surfaces within transitional zone between the Paleoproterozoic Dashiqiao and Gaixian formations of the Liaohe Group in the Jiao—Liao—Ji belt in NE China. Stratigraphic correlations of ore- hosted layers within the Dashiqiao and Gaixian formations are of great significances for regional and deep metallogenic predictions in the Qingchengzi ore concentration area. Here we present carbon—oxygen isotopes of 85 samples collected from the ore- hosted marbles and none ore- hosted marbles from the Dashiqiao Formation, and the previous named “Gaojiayu” Formation in the Qingchengzi ore concentration area. Our results show that the thick- layered none ore- hosted marbles from the middle—lower Dashiqiao Formation usually intruded by Paleoproterozoic metamorphosed mafic sills are characterized by positive carbon isotope excursion with δ13CV-PDB values of 2.1‰~6.1‰, and were deposited during late stage of the Lomagundi—Jatuli Event (LJE). In contrast, middle- to thick- layered ore- hosted marbles from the upper Dashiqiao Formation have δ13CV-PDB values from -6.4‰ to 3.0‰, and those from the previously named “Gaojiayu” Formation have δ13CV-PDB values from -2.8‰ to 0. Both the ore- hosted marbles from the upper Dashiqiao Formation and marbles from the previously named “Gaojiayu” Formation exhibit no positive carbon isotope excursion, indicating that their deposition occurred after the LJE. The carbon isotopic compositions of marbles from previously named “Gaojiayu” Formation in southeastern Qingchengzi ore concentration area are significantly different from those of marbles from the Gaojiayu Formation from Anshan area in northwestern part of the Jiao—Li—Ji Belt that are characterized by high positive carbon isotope excursion with δ13CV-PDB values of 10‰, indicating their depositional ages are different. Carbon—oxygen isotopes in combined with stratigraphic lithology show that leptites from the previously named “Gaojiayu” Formation, which are considered as the lower floor of gold and Pb—Zn—Ag ore deposits in the Qingchengzi ore concentration area, are stratigraphically correlated with the upper Dashiqiao Formation. The depositional age of the previously named “Gaojiayu” Formation of “South Liaohe Group” in the Qingchengzi ore concentration area is younger than that of the Gaojiayu Formation of “North Liaohe Group” in Anshan area. Combined with previous research results and exploration achievements, we proposed that multiple silicon—calcium surfaces and mineralization zones may exist beneath the current exploration areas of the Qingchengzi ore concentration area, especially the Linjiasandaogou, Xiaotongjiabuzi and Gaojiabuzi—Fengyindadi deposits. The deep areas of the Linjiasandaogou and Xiaotongjiabuzi deposits and Gaojiabuzi—Fengyindadi Pb—Zn—Ag deposit can be considered as favorable targets for deep metallogenic exploration the Qingchengzi ore concentration area. The future deep metallogenic exploration for the Linjiasandaogou, Xiaotongjiabuzi and Gaojiabuzi—Fengyindadi deposits should reach the thick- layered marbles of the middle—lower Dashiqiao Formation with positive carbon isotope excursions and intrusions of the Paleoproterozoic metamorphosed mafic sills.