The present invention provides a soil erosion prevention agent which is excellent in the freeze-thaw stability while maintaining the soil erosion prevention effect. A soil erosion prevention agent of the present invention comprises a water-borne resin emulsion; and a water-soluble polymer, wherein a content of the water-borne resin emulsion is 99 to 93 mass %, a content of the water-soluble polymer is 1 to 7 mass %, and the water-borne resin emulsion contains 0.01 to 0.10 parts by mass of a structural unit derived from a polyfunctional monomer with respect to 100 parts by mass of a structural unit derived from a main monomer.
