Two sets of samples, one from upper layer of thermocline to surface and second set from 500 m to surface were made. Copepod fauna from these collections were studied in relation to the hydrographical properties of the water column. The bulk of the population above thermocline was composed of Paracalanidae forming about 27.6% to 76.7%. Poecilostomatoids namely Oncaeidae and Corycaeidae together with the cyclopoid Oithonidae constituted 16.6% to 43.5% in the upper stratum sampled. Though twenty species of calanoids frequently occur above thermocline only a few species namely Canthocalanus pauper, Nannocalanus minor, Undinula vulgaris, Euchaeta spp., species of Eucalanidae, Scolecithricella clenopus, Lucicutia flavicornis, Candacia catula and Heterorhabdus papilliger were the regular components. In collections from 500-0 m Pleuromamma indica was the most dominant calanoid species and formed 37.7% of calanoid and 19% of total population