Observations on distribution of chlorophyll a, phaeopigments, zooplankton and physico-chemical parameters in the Southern Ocean were carried out during 9th Indian Antarctic-Expedition (1989-1990). The results indicated high phytoplankton biomass in terms of chl. a. The values of chl a and phaeopigment ranged from 0.51 to 6.4 and 0.05 to 0.62 mg/3, respectively. The zooplankton standing stock (biomass) values fluctuated between 3.1 and 62.2 ml 100/1 m/3 and showed an inverse relationships with chl a and phaeopigments. Copepods, euphausiids, decapods, polychaetes and chaetognaths were the major constituents of zooplankton community. The salinity values varied from 34.06 to 36.14 x 10/3. Temperature fluctuations of the seawater were pronounced (-0.5 to 29.5˚C) and seemed to influence the distribution and abundance of plankton. The nutrient concentrations at various stations were high.