Separation of Bicarbonate had been investi gated using a non-suppress cation chromatography and conductivity detection. Analysis was performed on an Optimix C18/SCX Cation-exchange column coupled to a conductivity detector, with an injection volume of 25 μL and a flow rate of 0.2 mL/min. The leacheate was fermentation of cyanobacterial apart from sodium bicarbonate. Under the optimized conditions, the linear relationship of Bicarbonate was 0.99946 in the range between 01 and 500 mg/L. The relative standard derivations of Bicarbonate less than 1.0% (n = 8). The recoveries of Bicarbonate in the samples from 100.15% to 111.10% were obtained. The Limit Of Detection (LOD) was 0.5 mg/L. The result showed that the method was convenient and accurate for the determination of Bicarbonate in Cyanobacterial fermentation.