Abstract: To study the environmental impacts of carbon and nitrogen flows during poultry scale-breeding in Chaohu Lake Basin, life cycle assessment (LCA) methodology was used to analyze the carbon and nitrogen footprints of poultry scale-breeding. The system covered four stages including feed cultivation, feed processing, poultry breeding, and manure management. Then both carbon footprint and nitrogen footprint resulting from poultry scale-breeding in Chaohu Lake Basin from 1990 to 2020 were analyzed. The results reveal that the carbon footprint increased and then decreased. Between 1990 and 2010, the carbon footprint surged from 0.3×10⁶ to 1.5×10⁶ t CO₂-eq. However, it then decreased to 0.9×10⁶ t CO₂-eq in 2020. Notably, the feed cultivation contributed a much higher carbon footprint than other stages, ranging from 56.0% to 71.3%. The nitrogen footprint exhibited the similar trends, increasing from 0.2×10⁵ to 1.1×10⁵ t Nr-eq between 1990 and 2005, and subsequently declining to 0.8×10⁵ t Nr-eq by 2020. This change was primarily attributable to the feed cultivation and manure management stages, which accounted for approximately 70% of the total carbon footprint and 30% of the total nitrogen footprint, respectively. The spatial distribution of carbon and nitrogen footprints from poultry scale-breeding in Chaohu Lake Basin was predominantly concentrated in the western area, particularly Feixi County. In 2020, Feixi County contributed 31.5% of the total carbon and 29.3% of the total nitrogen footprints, respectively. Therefore, some recommendations are proposed, including enhancing the control of agricultural inputs consumption during the feed cultivation stage, innovating the technologies for manure management and treatment, reconfiguring the structure of poultry scale-breeding, and strategizing the regional breeding scale. This study is not only helpful to the enrichment of researches on environmental footprint of poultry breeding within watershed, but also to the promotion of the sustainability of local agriculture.