To solve the frequent needs of spraying antifreezing admixture, if the face of slope is stabilized by a spraying material, it is repeatedly expanded and shrunk as a result of snowfall or freezing in a cold area, then the binding of the spraying material is greatly lowered by the action stated above, and cracking or smashing of the sprayed material occurs and the fixability of the sprayed material is lost and thus antifreezing admixture has to be sprayed but the antifreezing admixture has no persistence in its performance and therefore the spraying becomes necessary every time when the freezing occurs.

In the stabilizing method in which a desired spraying material B is sprayed for stabilizing a face of slope A, an antifreezing agent C is improved by giving an adequate delay means to the face of slope A, and then the persistence can be given to the antifreezing admixture.