Abstract—This study aims to assess the influence of socioeconomic activities on surface water quality in the Ca Mau province. Water quality data were collected at 14 locations in 2021. Water quality index (VN_WQI), hierarchical cluster analysis (HCA), Pearson correlation and principal component analysis (PCA) were applied in the study. The results showed that the surface water quality was contaminated organic matters (TSS, BOD, COD) and coliform. Water quality was assessed from poor to medium levels by VN_WQI and the water quality is unsuitable for direct irrigation purposes. The results also showed that water quality at Ganh Hao river fork (S2) was the most polluted. HCA classified water quality into three groups based on the similarity of water quality parameters. Pearson correlation results indicated organic pollution, nutrients and microorganisms were mutually related. PCA explained 83.60% of the total variance with three PCs. Ten parameters were identified as the key water parameters influencing surface water quality and these parameters should be continuously monitored. The water pollution sources were possibly urban and market activities, production facilities discharge and salinity intrusion.