In current study, anaesthetic effects of sodium bicarbonate (NaHCO3) in 6 concentrations were determined in common carp (Cyprinus carpio) juveniles (7.70+/-0.4 g and 8.38+/-0.8 cm) kept in two different pH levels and at 23 degrees C water temperature. Its effective concentrations were 1000 and 600 mg L-1 in pH 6.5 and 7.7, respectively. While stage of anaesthesia and recovery time increased, induction time decreased; opercular rate firstly increased but than slowly decreased with increasing the concentration of anaesthetic in both pH. No mortality was observed ill the study. Applications of NaHCO3 in high pH levels, seems to be suitable on anaesthesia of common carp.