Zooplankton biomass and their protein, lipid and carbohydrate were estimated from Kochi, Kozhicode and Kannur regions of the Arabian Sea. Biomass (ml/100 m^3) varied from 25.2 to 42 ml/100 m^3. Protein formed the major component, varied from 21.07 to 40.73%. Lipid content was ranged from 11.02 to19.61 % and carbohydrate (5.83 to 14.98%). The carbohydrate content was recorded maximum (14.98%) in Kannur region and which also expressed the minimum protein content (21.07%). M aximum % of protein (40.73%) and minimum levels of lipid (11.02%) and carbohydrate (5.83%) were noticed in Kochi region. Maximum % of lipids (19.62%) was observed in Kozhicode region.