Chillia fish hatchery ponds and Keenjhar Lake is located at Thatta district, water samples from Chillia fish hatchery ponds and Keenjhar Lake were analyzed for physicochemical properties and phytoplanktonic population during 2004 to 2007. The Keenjhar Lake water was slightly alkaline in nature, the range of physicochemical parameters were as, 265-372 mg L-1, 7.2-8.3, 159-218 mg L-1, 35-70 mg L-1, 18-30 °C, 50-73 mg L-1, 28-330 mg L-1, 7.2-8.5 mg L-1 and 320- 495 µS cm-1, and physicochemical parameters of Chillia fish hatchery ponds were as 124-187 mg L-1, 7.4-8.4, 65-86 mg L-1,21-25 mg L-1, 16-38.5 °C, 47-65 mg L-1, 18-25 mg L-1, 5.4-6.4 mg L-1, and 5.4-6.4 µS cm-1, for total dissolve solids, pH, alkalinity, chlorides, temperature, calcium, magnesium, dissolve oxygen and electrical conductivity respectively. A total 152 phytoplanktonic species belonging 49 genera were identified, as Cyanophyceae (83 spp), Chlorophyceae (57 spp), Bacillariophyceae (10 spp) and (1 spp) each belongs to Euglenophyceae and Xanthophyceae from Chillia fish hatchery ponds and Keenjhar Lake. Physicochemical properties of Chillia fish hatchery ponds and Keenjhar Lake were suitable for growth of aquatic biota. Keenjhar Lake was richer in primary productivity rather than Chillia fish hatchery ponds.