Giant freshwater prawn Macrobranchium rosenbergii i s one of the popular market demand and valuable species as freshwater crustacean delicacy especially in Asia markets. However, farming of giant freshwater prawn is experiencing inconsistent quality and quantity of post-larvae supply. L imitation of quality seed production is believes due to changing of environment quality that influencing overall food chain availability and habitat lost in nature. Although artificial seed production technology have been established for decades, but hatchery seed production still rely on wild broodstock collection. Thus, overall giant freshwater prawn seed production remain uncertain. In order to produce high quality and consistent quantity post-larvae, ensuring early life performance is a crucial key to culture freshwater giant prawn successfully. Among the environment factors, water pH is one of the factor affecting early life performance. Small degree of water pH fluctuation is known to pose significant impact to biological processes of aquatic life. Therefore, this study was planned to examine the effect of water acidification on early life performance of freshwater giant prawn with specifically focus on feeding, growth and molting performances. Experiment was designed with three different acidic water pH (neutral - 7.7±0.4; mild-acidic - 6.4±0.5 and acidic - 5.4±0.2 by using HCl titration ) in triplication with stocking density at 50 larvae/L. Throughout 30 days culture period, feeding rate, survival, growth and molting stage to post-larvae were monitored. As expected, giant freshwater prawn highly sensitive to acidic pH with no larvae survive beyond 48h under acidic condition . Meanwhile, larvae exposed to mild-acidic pH significantly depressed feeding, growth and survival rates as compared to neutral pH. Larvae exposed to mild-acidic water pH experiencing longer larvae period for 30 days prior metamorphosed into post-larvae stage. Whilst under neutral water pH, larvae metamorphosed into post-larvae was record ed at day-22. Ultimately, this study proved that giant freshwater prawn M. rosenbergii larval is highly sensitive to acidification and farming of this species should be avoided from low water pH condition.