An experimental study has been performed to investigate the freezing characteristics of aqueous binary solution along a horizontal cooled tube. A copper tube 41.2mm in diameter was set horizontally in the flow duct which has cross-sectional dimensions of 120mm × 200mm. Ethylene-glycol solution was utilized as a test solution. Concentration of the solution, initial temperature, cooling temperature, and flow velocity were set as parameters, and observation of frozen layer and visualization of flow pattern were extensively carried out. It was found that the characteristics of frozen layer could be well grouped using both the Reynolds number and the cooling temperature ratio, and that the flow field provided a considerable effect on the characteristics of the frozen layer. The correlation equation of averaged frozen layer thickness in the steady state was determined.