An experimental study has been performed to investigate the freezing characteristics of an aqueous binary solution along a horizontal cooled tube. A copper tube 41.2 mm in diameter was set horizontally in a flow duct which has cross-sectional dimensions of 120 mm × 200 mm. Ethylene-glycol solution was utilized as a test solution. The 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 the frozen layer could be well grouped using both the Reynolds number and the cooling temperature ratio, and that the flow field had a considerable effect on the characteristics of the frozen layer. The correlations of the averaged frozen-layer thickness at the steady-state were determined.