Abstract: Based on the study of ionic characteristic and electrochemical activity,a method of ion-chromatography with amperometric detection for qualitative detection of sodium formaldehyde sulfoxylate (CH2O·HSO-2·Na+) was proposed.Effects of temperature and acidity on the stability of the analyte were tested and discussed.In the quantitative testing,values of recovery found were ranged from 90% to 96%.Values of RSD′s (n=5) calculated from the analytical results were all less than 4%.