Abstract: A simultaneous determination of mannose, glucose and calcium gluconate formed in mannose production by using capillary zone electrophoresis combined with electrochemical detection(CE-ED) is reported. The effects of working electrode potential, running buffer concentration, separation voltage and injection time on the determination were examined. Mannose, glucose and calcium gluconate could be well separated in a 60 mmol/L NaOH buffer within 16 min. A 300μm diameter copper disk electrode was used as a working electrode at a potential of 0.65 V(vs.SCE). A good linear relationship between peak current and analyte concentration in the range of 2.0~0.01 mmol/L was obtained with detection limit of 6.1 μmol/L、7.1 μmol/L and 3.7 μmol/L for mannose, glucose and calcium gluconate, respectively. The RSD of the peak currents for the analytes were 3.6%, 2.4% and 3.8%(n=7), respectively. Recoveries for mannose, glucose and calcium gluconate were 100.6%, 100.1%, and 98.9%(n=3) respectively.