Abstract: Nanchang, a typical waterfront city in Southern China, experiences substantial anthropogenic influences on the hydrochemistry of its urban lakes. However, there is a lack of research on the impacts and underlying controls. In this study, the Nanchang urban lakes (Yaohu Lake, Aixihu Lake, Qingshanhu Lake and Xianghu Lake) and rivers (Ganjiang River and Fuhe River) were taken as the objects. Combined with correlation analysis, principal component analysis (PCA), Gibbs diagrams, and ion ratios, the pH, electrical conductivity (EC), total dissolved solids (TDS), and anion/cation concentrations of water samples collected from November 2020 to October 2021 were studied to reveal the hydrochemical characteristics and their influencing factors. Results show that the Nanchang urban lakes had a slightly alkaline pH range (7.81-8.05) and TDS values were 110-364 mg·L^-1. Aixihu Lake exhibited a unique hydrochemical type of SO₄^2--HCO₃^--Mg²⁺-Ca²⁺-Na⁺ due to industrial pollution, while other lakes were predominantly of the HCO₃^--SO₄^2--Ca²⁺-Na⁺ type. Unlike the rivers, the ionic concentrations of lakes showed decreasing trends during the rainy season with the lowest levels in August, indicating reduced anthropogenic pollutant inputs from rainy season flushing. Multivariate analysis reveals that peripheral lakes (Yaohu, Xianghu) were significantly influenced by silicate weathering, whereas central urban lakes (Aixihu, Qingshanhu) were predominantly affected by anthropogenic activities like industrial pollution, municipal sewage, and agricultural fertilizer. This study highlights the complexity of hydrochemical characteristics in Southern China′s urban lakes, underscores the substantial impact of human activities on water quality, and provides a scientific basis for urban water environment management.