To eveluate the paleoceanographic information recorded in the stratigraphic record,carbon and oxygen isotope analyses were conducted for 83 carbonate rock samples from the Longwangmiao Formation of the Lower Cambrian along with outcrop study and thin section analysis. The results (excluding invalid samples)show that the delta~(13)C values of carbonate rocks in Longwangmiao Formation vary from-4.300 to 2.694 with the mean value of-0.031 and the delta~(18)O values vary between-9.880 and-0.100 with the average of-7.396. The vertical variation of delta~(13)C shows a decrease trend followed by an increase trend from bottom to top of the studied interval. The carbon isotopic composition is characterized by negative values with frequent occurrences of positive or negative excursions at the lower to middle part of the formation and positive values with small fluctuation at the other parts. The reconstruction of palaeo-ocean environments shows that marine environment was developed around the eastern Chongqing area during the Lower Cambrian Longwangmiao stage. The salinity of seawater was low during the Early Longwangmiao stage and high during the later stage. Sea water temperature mainly ranged between 20℃ and 30℃,suggesting a warm to hot subtropical climate. Three stages of regression-transgression cycles through Longwangmiao stage were identified. When sea level rises,increased marine productivity and fast burial of organic carbon result in an increase of delta~(13)C value. In the case of dropping sea level,the delta~(13)C value decreases. During the middle to late Longwangmiao stage,the negative shift of delta~(13)C value,low seawater level and the high salinity provide favorable conditions for the development of dolomites.