The current study focuses on the physicochemical parameters including phytoplankton and zooplankton diversity of marine water ponds at Thatta district, Sindh, Pakistan. Water samples were collected monthly ( Jan-Dec, 2019) from diferent sites of the ponds and studied the total abundance of plankton in each month. During the study, physicochemical parameters of the pond water like temperature, pH, dissolved oxygen, salinity, transparency, ammonia, phosphates, nitrates, potassium, calcium, total alkalinity and total hardness were determined. Overall, 61 species of plankton have been recorded from the studied ponds and categorized into 19 groups; of which 25 phytoplankton species belonged to four major groups, whereas, 36 zooplankton species belonged to 15 groups. Among them, Bacillariophyta (69.815%) and copepods (78.927%) were “most abundant” as compared to other groups of phytoplankton and zooplankton, respectively. Monthly abundance of phytoplankton and zooplankton was observed and the highest percentage was found in the month of November (18.559%) and July (16.560%), respectively. The optimal range of physicochemical parameters of the pond water with planktonic diversity indicates the productivity of water which is crucial for the growth of pond biota during pisciculture activities.