Crystals of a salt of 4'-{2-[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethylamino]ethoxy}-3- -isopropyl-3', 5'-dimethylbiphenyl-4-carboxylic acid. The .alpha. type, .beta. type and .gamma. type crystals produced by treating hydrochloride of 4'-{2-[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl-amino]ethox- y}-3-isopropyl-3',5'-dimethylbiphenyl-4-carboxylic acid with specified solvents, which can be discriminated by the characteristic diffraction peaks of powder X-ray diffractometry and the like.