Novel 1,2-dihydronaphthalene derivatives of the formula ##STR1## wherein R.sup.1 and R.sup.2, independently of each other, are hydrogen, nitro, amino, halogen, or hydroxyl which may be protected, and R.sup.3 is a piperazinyl or morpholino group which may be substituted by lower alkyl, aralkyl, carboxylic acid-derived acyl, lower alkoxycarbonyl-lower alkyl or cycloaminocarbonyl-lower alkyl, and its salts have excellent pharmacological activities such as vasodilator and cerebral blood flow increasing activities.