A tetrahydronaphthalene derivative of the formula: ##STR1## wherein R.sup.1 is a substituted or unsubstituted phenyl group, naphthyl group, a sulfur- or nitrogen-containing heterocyclic group, a lower alkyl group or cycloalkyl group, and R.sup.2 is hydroxymethyl group, carboxyl group, a lower alkoxycarbonyl group or a group of the formula: ##STR2## wherein R.sup.3 is hydrogen atom or a lower alkyl group, R.sup.4 is a lower alkoxycarbonyl-phenyl group, carboxy-phenyl group, a lower alkyl group, a lower alkoxycarbonyl-lower alkyl group or carboxy-lower alkyl group, and m and n are different and are 1 or 2, or a pharmaceutically acceptable salt thereof, which are useful as a platelet aggregation-inhibiting agent and as an agent for the treatment, amelioration and/or prophylaxis of a variety of thrombosis or embolism, coronary and cerebral vascular smooth muscle vellication, asthma, and the like, processes for the preparation thereof, and pharmaceutical composition containing said compound as an active ingredient.