Abstract: Replacing fine grained subsoil with sandy gravel for preventing structures from frost damage is widely and effectively used in cold regions at home and abroad. The frost heave ratio, as an index of classification of frost susceptibility for sandy gravel, mainly depends on not only the. content of fine grained soil but also its freezing condition. Our experimental results show that the frost heave ratio, η, of sandy gravel in open system increases with the increase of the content of fine grained particle, C, and with the decrease of the frost penetration rate, V1, as a power function, and can be expressed by η = B0VfB1CB2 satisfactorily. Graphical solutions have been given, which might be very useful for designing the size distribution and the thickness of sandy gravel cushion, and the depth of foundation reasonablely.