Abstract: The distribution and abundance of female and male of Paracalanidae presented within the near shore and off shore waters of Chabahar Bay. Paracalanidae conducted from zooplankton sampling during four oceanography cruises August 2007 (SW-monsoon), November 2007 (post-monsoon), February 2008 (NE-monsoon) and May 2008 (pre-monsoon). Five stations were investigated throughout the Bay. Paracalanidae represented by Acrocalanus (A. longicornis, A. gracilis, A. gibber, A. monachus and Acrocalanus sp.) and Paracalanus (P. aculeatus, P. denudatus, P. parvus, P. crassirostris, P. elegans and P. indicus). Two-way ANOVA showed that difference in Paracalanidae abundance amongst periods and locations was significant (p<0.05). Our result showed that environmental parameters (temperature, salinity, chlorophyll-a, pH, DO and depth) influence on the abundance and distribution of both sexes of Paracalanidae species. Paracalanidae female always outnumbered than males. The reason could be that copepod adult males live for shorter periods than females. Also sex change could be in some Paracalanidae species from copepodite stage 5 male to female.