ABSTRACT-Fresh water resources are not unlimited. The high rate of increase of human population of Nepal and the rapid rate of industrialization have created problems of disposal of waste water products. The domestic wastes, excretory materials of both human and animals and industrial effluents are discharged into the nearly lakes, rivers, reservoirs and tanks and even in the catchment area of the above water bodies. The undesirable substances are regularly mixed into the water of pond through surface run-off that degrades the water quality. Since last several years, there have been added an array of agricultural pesticides and insecticides, which are further seriously aggravating the problem of pollution both for public health and aquaculture. The detailed information of water quality and status of affected living organisms of water bodies are necessary for the implementation of any management plan. The present investigation encompasses on plankton identifying the ecological quality of Chhapakaiya pond Birgunj, Nepal. Seasonal sampling from all the sampling sites (site A, B, C, D) in winter, summer and rainy season for period of 12 months (November 2014 -October 2015 at 9:00-11: 00 AM. A total of 27 taxa from different classes of zooplankton were reported. The zooplanktons were reported to be maximum (774.4 unit/L) during summer and minimum (539.2 unit/L) during the rainy season in Chhapakaiya pond.