Study on water quality and zooplankton diversity of Kallambella tank, Tumkur district, Karnataka, India was conducted to check the status in the area and provide new insights into its ecology. The samples were collected during June 2016 May 2017. A total numbers of 4703 species were found in this tank. Among these rotiferous comprised of 12 species (41.36%), cladocera 5 species (30.55%), copepods 3 species (23.16%) and ostrocoda 2 species (4.9%). The result of present investigation are compared with the literature values and investigation reveals that there is fluctuation in the physico-chemical characteristics of the water.