Research on water quality assessment of Hau river in An Giang province was conducted in 2019 in the upper Hau river (SH-T) and downstream Hau river adjacent to Can Tho (SH-H) through the following physico-chemical parameters, heavy metals: temperature, pH, Dissolved Oxygen (DO), COD, BOD5, Total Suspended Solids (TSS), Nitrate (NO3by N), Phosphate (PO4 3by P), Coliform, Arsenic (As), Lead (Pb), Mercury (Hg), Ammonium (NH4 + by N) and zooplankton system. Research results showed that: (1) Surface water quality in the area showed signs of pollution, DO content: 3.02-5.97 mg/l, lower than the standard (≥ 6 mg/l); TSS parameters: 35-90 mg/l, 1.75-4.5 times higher than standard; COD: 10-23 mg/l, 1.1-2.2 times higher than standard; BOD5: 7-14 mg/l, 1.75-3.5 times higher than standard; Ammonium: 0.039-1.14 mg/l higher than standard 1.63 times in March and 3.83 times in September; Coliform: 2.100-24.000 MNP/100ml, not guaranteed well according to QCVN 08-MT:2015/BTNMT (level A1); (2) Surface water quality in the upper Hau river area according to diversity index H': 0.91 in March at "Heavily polluted" and H': 1.89 in September, at "Moderately polluted"; (3) The results of statistical analysis and PCA showed that the water quality parameters had significant differences between the two seasons, the rainy season showed signs of Coliform pollution and TSS more than the dry season.