Abstract: Based on the survey data of 21 stations in Lingdingyang in the summer of 2019, this study analyzes the distribution patterns and influencing factors of the dissolved heavy metals in estuarine waters, and investigates the impact of estuarine dynamics and eutrophication on the heavy metals. Correlation analysis along with principal component analysis-multiple linear regression model (PCA-MLR) are used to quantitatively identify the sources and contribution rates of heavy metal pollution. The results indicate significant spatial variations of seven heavy metals. Cr, As, Zn, and Cu generally exhibited a decreasing trend from the upper estuary to the mouth, with concentration ranges of 0.17-0.95, 2.8-5.0 3.59-12.66, and 1.02-4.05 μg·L⁻¹, respectively. In contrast, Pb, Hg, and Cd showed different trends, with concentration ranges of 0.16-1.72, 0.014-0.029, and 0.04-0.09 μg·L⁻¹, respectively. These differences are associated with anthropogenic pollution, industry, agriculture, and domestic sewage discharge in the coastal areas. Eutrophication assessment revealed that the Lingdingyang Bay is classified as “medium to high” eutrophication level, which is significantly correlated to the distribution characteristics of heavy metals (e.g. As, Cu, and Zn). Ecological risk evaluation results showed that the heavy metals in the study area are generally at “mild to moderate” pollution levels, with Cu, Zn, and Cd being the main pollution elements. Pearson correlation analysis showed that As, Zn, and Cu originate from similar pollution sources, Cr and Hg have similar sources, and Pb and Cd come from distinct sources different from the others. The PCA-MLR results identified four main sources of heavy metals in the surveyed sea area: industrial sources contributed the most (29.5%), followed by transportation sources (25.1%) and natural sources (23.0%), while agricultural pollution sources had the smallest contribution (22.4%). This study provides improtant insights into the transport and transformation of heavy metals in estuarine areas influenced by human activities. It also offers critical support for integrated land-sea pollution prevention and control in the Pearl River Estuary and ensures water security in the Guangdong-Hong Kong-Macao Greater Bay Area.