PURPOSE: To obtain a dental pretreating agent capable of strongly bonding a dentin part and enamel part to a restorative part not followed by pain of a patient, suppressing damage of dentin, not requiring a time, containing a surfactant.

CONSTITUTION: This dental pretreating agent contains preferably 0.001-10wt.% of a surfactant. The surfactant may be an anionic, a cationlc, a nonionic or an ampholytic one. The surface preferably has pH1 to pH8 in any kind. Sodium dioctylsulfosuccinate and sodium dodecylbenzenesulfonate are preferable as the anionic surfactant. A polyethylene glycol mono-p-isooctyl phenyl ether is preferable as the nonionic surfactant. An adduct of a higher alkylamine with ethylene oxide and an alkyltrimethylammonium salt are preferable as the cationic surfactant. The treating agent may be preserved in a container divided into a section containing the surfactant and a section containing other components.