PROBLEM TO BE SOLVED: To provide a urethane-based coating material for protection of the ground surface which reacts with a reduced amount of water, compared with conventional coating materials, to form durable hydrous gel and is friendly to the environment, e.g. leaving no unreacted TDI.SOLUTION: A coating material for protection of the ground surface contains a urethane polymer which is a product of a reaction of a polyol component (A) containing a urethane prepolymer having terminal hydroxy groups with an organic polyisocyanate (B) and has terminal isocyanate groups.
