Abstract: A diphenylpiperazine derivative represented by general formula (1), salt thereof, and drug for the circulatory organs containing the same as the active ingredient: ##STR1## wherein R.sup.1 and R.sup.2 may be the same or different from each other and each represents hydrogen, halogen, alkyl, alkoxy, nitro, amino, hydroxy, optionally esterified carboxyl or trifluoromethyl; R.sup.3 represents hydrogen, alkyl, aralkyl, acyl, nitro or optionally esterified carboxymethyl; Ar represents phenyl or naphthyl which may have one to three substituents such as halogen, alkyl, alkoxy, aryloxy, aralkyloxy, nitro, amino, cyano, acyl, hydroxy, optionally esterified carboxyl, substituted sulfonyl, aryl or trifluoromethyl; Z represents sulfur or -NR.sup.4 - wherein R.sup.4 represents hydrogen, alkyl, aralkyl, acyl, aryl, substituted sulfonyl or optionally esterified carboxyl; m represents a number of 1 to 5; and n represents a number of 0 to 5.