This study was carried out with the aim to determine the diversity of zooplankton composition as a basis data for the evaluation of natural food resources in the study area. The study was carried out with two sampling times (12/2013 and 03/2014). Zooplankton samples were collected at 14 sites including 5 sites on the Hau river and 9 sites on its tributaries. The result indicated that there were 90 zooplankton species, in which rotifer contributed 45% (40 species), followed by copepods (17 species, 19%) and others varying from 7-13 species (8-14%). Zooplankton composition on the Hau river was lower than that on its tributaries during study period. The mean of zooplankton composition in Hau river was the highest at Thot Not and lowest at Can Tho. In the tributaries, species number was the highest at Bo Ot canal and lowest at Cai Rang river. The mean of zooplankton density of Hau river was lower than that of its tributaries. The Sorensen?s similarity index about zooplankton composition between Hau river and its tributaries was 0.61. Average Shannon-Weaver diversity index of Hau river and its tributaries was 2.41±0.32 and 2.42±0.40, respectively. In conclusion, zooplankton in research area was quite diversity and natural food source useful for aquatic animal larvae.