Strip-shaped steel (Strip) reinforced earth walls have been in use for more than 45 years．As a measure against aging or disaster, maintenances of reinforced earth walls will be required in the near future. Conventional chemical grouting has been used for stabilizing soil behind a wall when replacing the wall surface during maintenance. However, the injected chemical grout may affect the permeability of the drainage layer behind the wall surface. Therefore, the ground freezing method, which enables the reinforcement of the ground without grout materials, has gained attention. However, the ground freezing method is ordinarily applied to saturated soil. Therefore, the applicability of this method to unsaturated soil such as Strip reinforced soil was examined. CO2 was used as a refrigerant for the cooling system, and the working space was reduced. In the full-scale experiment, 6 freezing pipes with 60.5 mm in diameter were installed at 0.6 m intervals behind the wall in a 10.8 m×2.4 m artificial fill. After 4 days freezing, the surface of the reinforced earth wall was replaced successfully without the soil collapsing. From the results of the laboratory experiment and comparisons to a model for saturated soil, it was found that, when the saturated soil water content is 0.4 m3 m-3, the unsaturated water content ranged from 0.2 to 0.3 m3 m-3 is required in order that the freezing rate of the unsaturated soil should be equivalent to the one of the saturated soil. Further investigation, such as the influence of water content and water flow on freezing expansion and construction technique at the time of wall surface replacement, will be needed to establish this technique.