The western Qaidam Depression features rich Paleogene-Neogene petroleum systems, with conventional and shale oil accounting for 82.4 % and 100 % of the counterparts of the whole basin, respectively. Based on the investigated sedimentary reservoirs and petroleum geology, we analyze the sedimentary facies and hydrocarbon accumulation characteristics of the Paleogene-Neogene in the western Qaidam Depression and propose a ring-shaped hydrocarbon distribution pattern therein. The results reveal that the Paleogene-Neogene sedimentary facies zones in the depression present a ring-shaped distribution pattern comprising outer, middle, and inner rings. The outer ring, featuring deltaic and beach-bar facies, is dominated by clastic sediment, with the presence of small quantities of carbonate sediment. This ring contains conglomerate, coarse-grained conglomeratic sandstone and medium-grained sandstone reservoirs. The middle ring is dominated by the limy dolomite flat and limy muddy flat microfacies of the shore-shallow lacustrine subfacies, including fine-grained sandstones, siltstones, limy dolomites, and algal limestones. Of these, algal limestones serve as the most distinctive lithofacies with the highest porosity observed in the middle ring. The inner ring is composed of fine-grained diamictites of the semi-deep to deep lacustrine facies, encompassing deep-and dark-gray fine-grained sedimentary rocks. This establishes the middle ring as the key area to source rock development in the Paleogene-Neogene system. Reservoir types differ across the different sedimentary facies rings. In the outer ring, which is distant from hydrocarbon kitchens, hydrocarbons, transported via faults, accumulate in clastics such as conglomerates and coarse-grained sandstones, resulting in structural hydrocarbon reservoirs. The middle ring, immediately adjacent to the major hydrocarbon kitchens, has hydrocarbons migrating through faults and accumulating in carbonate reservoirs like algal limestones, resulting in the structural-lithological hydrocarbon reservoirs. The inner ring sitting on major source rock sequence has hydrocarbons either undergo shortdistance migration or reside in situ in fine-grained diamictites, forming shale oil reservoirs. The western Qaidam Depression exhibits overlapped structural-lithological hydrocarbon reservoirs and shale oil reservoirs vertically from external to intra source rocks, and manifests a ring-shaped distribution of structural hydrocarbon, structural-lithological hydrocarbon, and shale oil reservoirs in a plan view.