<p><span style="font-size:14px"><span style="font-family:Arial,Helvetica,sans-serif">Study of a water body at Jammu was carried out for a period of one year from January 2004 to December 2004 to observe various water quality parameters and zooplankton dynamics. Temperature, Dissolved oxygen, Free Co₂, Carbonates, Bicarbonates, Calcium, Magnesium and Chlorides were estimated on monthly basis. A total of 12 zooplankton species were identified comprising of three major planktonic groups viz. cladocera, rotifera, and copepoda. Moina among cladocera and Brachionus among rotifera were present at high as well as low DO level, therefore revealing their wide tolerance for oxygen variation. Dominance of Copepods during period of high pollution characterized by high temperature, high Free CO₂and low level of Ca⁺⁺ and Mg⁺⁺ reveals their importance as pollution indicators. Zooplankton population was mainly contributed by cladocerans (46.39%) followed by rotifers (44.12%) and copepods (9.48%).</span></span></p>