Abstract: By gathering and scrutinizing environmental DNA (eDNA) samples within the Yangtze estuary, using fluorescence quantitative PCR (qPCR), and by integrating data from the Eriocheir sinensis parent crab resource surveys, we have delved into the potential applications of environmental DNA technology in fisheries resource research. Our findings revealed that during the winter of 2022, the catch per unit effort (CPUE) for Eriocheir sinensis parent crabs in the Yangtze estuary was recorded at (269.14±184.77) g/net·h. The eDNA concentrations in both surface water and bottom water were (14332.06±30560.85) and (15691.27±45132.77) copies/mL, respectively. Notably, both eDNA concentrations exhibited a highly significant positive correlation with the CPUE of parent crabs, demonstrating correlation coefficients of 0.912 and 0.883. The most fitting models for CPUE and standardized eDNA concentrations in both surface and bottom water were determined to be linear models. Identified as pivotal environmental factors influencing the variation in Eriocheir sinensis eDNA concentration in surface water were identified as surface water salinity and bottom water turbidity. In this study, we have preliminarily established a quantitative analysis model for monitoring Eriocheir sinensis resources by observing relation in CPUE and eDNA of the Eriocheir sinensis during the winter in the Yangtze estuary. The results of this study not only provide a valuable reference for the surveillance of aquatic biological resources but also play a crucial role in guiding resource protection and habitat restoration.