The present invention provides a soil erosion prevention agent which is excellent in the freeze-thaw stability while maintaining the soil erosion prevention effect. When a toluene-insoluble matter of the water-borne resin emulsion is 60 mass % or more and a content of the water-soluble polymer in the soil erosion prevention agent is 1 to 7 mass %, preferably 3 to 5 mass %, the soil erosion prevention agent excellent in the freeze-thaw stability is provided and suitable for greening and a spraying material. The water-borne resin emulsion is preferably a resin containing a structural unit derived from vinyl acetate, or an ethylene-vinyl acetate copolymer emulsion.
