To provide a urethane resin composition having excellent performances as a protective coating for a concrete structure for water supply and sewerage, which has good workability because of its long applicable period, suppresses a foaming phenomenon even in the case of working in a high humid atmosphere, and further forms a coating film with excellent weatherability.

This urethane resin composition for protecting concrete structure for water supply and sewerage comprises (1) an isocyanate component comprising a modified matter of hexamethylene diisocyanate and (2) a polyol component including a liquid polyol and an aromatic multifunctional polyol with two to five hydroxy groups and having a number-average molecular weight in the range of 400 to 800.