The traditional production process for formic acid is a high-energy-consumption process. To save energy when concentrating formic acid solutions, anion-exchange membranes 3362W and AM-203 were evaluated for facilitating the concentration of formic acid solution by electro-electrodialysis. The effects of concentration, temperature. electric current, and time on the electro-electrodialysis process were studied. Experimental results indicated that electro-electrodialysis was an effective method for concentrating formic acid solutions at 30 degreesC. Higher efficiencies were not obtained at higher temperatures. If the concentration of a working system was greater than 10 wt%. The overall current efficiency was greater than 100%. The overall current efficiency was 80-95% when the concentration of a system was less than 10 wt%. In general, the overall current efficiency was increased with an increase of low current density. After a certain value, the overall current efficiency would begin to drop. The performance of the AM-203 membrane was better than the 3362W membrane. With the AM-203 membrane it was found that the overall current efficiency was decreased if the concentration difference between the cathodic and anodic compartments was increased.