Abstract: A snow-melting/antifreezing agent which comprises potassium silicate as an active ingredient and a snow-melting/antifreezing agent which comprises potassium silicate and a nitrite salt as active ingredients are disclosed. These snow-melting/antifreezing agents may optionally further contain an alkali metal salt and/or a lower alcohol. These snow-melting/antifreezing agents are safe for the environment and do not cause concrete to deteriorate. They not only have excellent capability to melt snow and ice and to prevent freezing, but also have high profitability and are easy to handle.