Non-marine ostracod, which is very sensitive to variations of the water body in which they live, is of importance to be used as an indicator to reconstruct the lacustrine environment. By analyzing the ostracodes properties such as shell morphology, ornamentation, disarticulated/articulated ratio, and degree of shell calcification, we try to reconstruct the paleoenvironment of the Sungliao basin, including the palaeogeography, palaeohydrology, palaosalinity and palaeoclimate. The two sections were measured in the east periphery of the Songliao basin. According to the ostracods assemblages, we refer the strata to the Qingshankou Formation. The Niaohe section is composed of the member 1 of the Qingshankou Formation, and the Hongshishan of the member 2 of the Qingshankou Formantion. Biostratigraphically, the Triangulicypris torsuosus—Triangulicypris torsuosus var. nota assemblage zone has been recognized in the Niaohe section, which can be correlated with other sections in the central Songliao basin, yet the biostratigraphy of the Hongshishan section can be correlated with the Cypridea dekhoinensis—Limnocyrpridea copiosa assemblage zone of the basin. The strata mentioned above were deposited in two distinctive environments. The Niaohe section is of the feature of sub-shallow water environment, which is characterized by the low biodiversity and extremely high abundance. The salinity is about 5‰ (brackish water). The Hongshishan section shows a shallow and fresh water (fresh to oligohaline water) environment characterized by the presence of gastropods, stoneworts and ostracodes with nodes. Generally speaking, the palaeoenvironmental change of Binxian depression during this period was identical with the Songliao basin, which implies that the Binxian depression sub-basin might be a part of an integrated Songliao basin at that time. Furthermore, the changes in ostracode palaeoecology between member 1 and member 2 of the Qingshankou Formantion suggest the changes in palaeohydrology of the period.