The present invention relates to 3,4-disubstituted phenylethanolaminotetralincarboxamide derivatives represented by the general formula: ##STR1## (wherein A represents a lower alkylene group; B represents an amino group, a di(lower alkyl)amino group or a 3 to 7-membered alicyclic amino group which may contain an oxygen atom in the ring; n is an integer of 1 or 2; the carbon atom marked with * represents a carbon atom in R configuration, S configuration or a mixture thereof; and the carbon atom marked with (S) represents a carbon atom in S configuration) and pharmaceutically acceptable salts thereof, which have a selective .beta..sub.2 -adrenergic receptor stimulating effect with relieved burdens on the heart such as tachycardia and are useful as an agent for the prevention of threatened abortion and premature labor, a bronchodilator and an agent for pain remission and stone removal in urolithiasis.