A concrete anticorrosive is provided to prevent corrosion of concrete and extend a life of concrete while removing sulfur ions present in an organic material and neutralizing sulfate ions as a strong base. A concrete anticorrosive is prepared by dissolving 5-20wt% of copper ions and 5-20wt% of nickel ions in water. The concrete anticorrosive further comprises liquid sodium hydroxide or/and potassium hydroxide. The sodium hydroxide or potassium hydroxide is contained in an amount of 10-50wt%. The copper ion is at least one selected from copper nitrate, copper bromide, copper chloride, and copper sulfate. The nickel ion is at least one selected from nickel acetate, nickel bromide, nickel chloride, nickel iodide, nickel nitrate, and nickel sulfate.