In the present study the distribution pattern and density of Ilyoplax frater as the larval stage of crab( family Ocypodidae) were studied by selecting six different stations covering both estuarines (Ramleh, Dubbeh, Shif, Lashkary), Creek-estuary region(farakeh) and Sea station in the northwest Persian Gulf, Bushehr Province waters within June 2015 to March 2016. MeroZooplankton samples were collected bimonthly and physico-chemical parameters (Transparency, Salinity, Temperature, pH, Chl-a) were also measured. In the temporal succession, major peak of I. frater zoea abundance occurred in the September 2015(11974±2359.40 N/m³) and minor peak occurred in Janaury 2016 (83.55± 25.96 N/m³). The highest and the lowest density of I. frater zoea with values of 9796.20 ± 2449.05 and 128.71± 33.99 N/m³were found for Ramleh and Farakeh stations, respectively. The DstLM (Distance Linear Model) test with considering the environmental factors and density of chlorophyll-a it was found that there is significant relationship between I. frater zoea density and some physical and chemical parameters with the most important factors of temperature and salinity in which effects on distribution of I. frater zoea in the study area.