PROBLEM TO BE SOLVED: To provide a dental adhesive which makes it possible to clearly and easily confirm its dry condition after application to a tooth.SOLUTION: A dental adhesive at least comprises (a) an acidic group-containing polymerizable monomer, (b) water, (c) a color changing material which makes it possible to confirm a dry condition of the dental adhesive after application to a tooth from a change in the developed color before and after drying, and a photopolymerization initiator.