A research on the effects of low pH on growth and survival rate of freshwater prawn (Macrobrachium rosenbergii) from post larvae to juvenile was carried-out with four treatments at the different pH values 5,6,7 and 8 (control). The stocking density was 30 PL/160L tank and PL were nursed. The results showed that pH, water temperature, dissolved oxygen, NH4+, NO3- during the experimental for 75 days period were suitable for prawn. The survival rate of freshwater prawn fluctuated from 53.3 to 75.6 %. The final mean weights of freshwater prawn were 0.5 - 2.2 g/juvenile. The daily weight gain of prawn fluctuated from 6.1 to 20.8 mg/day. Treatment IV was the highest survival rate of 75.6 %; at the different significance