This invention provides 2-aminoquinoline derivatives represented by a general formula [I] ##STR00001## [in which R.sup.1 and R.sup.2 either stand for lower alkyl, lower cycloalkyl, etc., or R.sup.1 and R.sup.2 together form an aliphatic nitrogen-containing heterocycle with the nitrogen atom to which they bind; R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 stand for hydrogen, lower alkyl, etc.; R.sup.8 stands for lower alkyl, lower alkyloxy, etc.; and n stands for an integer of 0-4]. The compounds act as melanin concentrating hormone receptor antagonist, and are useful as medicines for central nervous system disorders, cardiovascular disorders and metabolic disorders.