The Paleoproterozoic meta- supracrustal rocks, known as the Liaohe Group, are widely exposed in the Heigou area of the Liaoning province. In this paper, we study the petrology of the leptite, mica- quartz schist, tremolite granulite, biotite plagioclase, amphibolite, and hornblende adamellite, and undertake U- Pb dating of the zircons in these rocks. The aim is to constrain the petrogenesis of the Liao- Ji belt by investigating their composition, chronology, and metamorphism of the protolith, and petrogenesis. The zircon U- Pb dating results of the metamorphic volcanic rocks and the intrusive granites of the Liaohe Group in the study area show that the formation age of the Liaohe Group is older than～2. 16 Ga. The metamorphic zircon dating results of the Liaoji granitoids and the Liaohe Group metamorphic rocks show that the metamorphic age in the peak period is about 1. 85 Ga. Most detrital zircons from the meta- sedimentary rocks in the formation show oscillatory zones under Cathodoluminescence (CL) image indicating a magmatic origin. The U- Pb age distribution histogram of zircon shows the main peaks at 1987 Ma, 2182 Ma and 2505 Ma, and secondary peaks at 2080 Ma, 2658 Ma, 2732 Ma and 3000 Ma. The main peaks are consistent with the ages of regional upper Paleoproterozoic granitoids, volcanic rocks of the Liaohe Group, and the Archean basement, suggesting that they provide important provenance for the sedimentary rocks of the Nanliaohe Group. The deposition time of the meta- sedimentary rocks is later than 2. 0 Ga as constrained by the youngest detrital zircons. The amphibolite of the Liaohe Group in this area is characterized by low TiO2 and MgO values, slightly enriched in light rare earths, shows obvious loss of P, and a slight loss of Nb, Ta, Zr, indicating that it belongs to the tholeiite series. The geochemical characteristics are generally similar to MORB and IAB, which are different from arc basalts and intraplate basalts, showing limited subduction- related fluid metasomatism, indicating that it was formed in the back- arc basin environment. By comparing the previous research results on Paleoproterozoic granites and volcanic rocks of Liaohe Group in the Liaoji orogenic belt, we conclude that the sedimentary environment of this group in the study area was an active continental back- arc basin, and the formation and evolution of the Liaoji orogenic belt is related to arc- land collision.