A melanin-concentrating hormone antagonist comprising a compound of the formula: ##STR00001## wherein R is hydrogen atom or a cyclic group which may be substituted; X is a bond or a spacer having a main chain of 1 to 10 atoms; Y is a spacer having a main chain of 1 to 6 atoms; ring A is benzene ring which may be further substituted; ring B is a 5- to 9-membered nitrogen-containing non-aromatic heterocyclic ring which may be further substituted; R.sup.1 and R.sup.2 are the same or different and are hydrogen atom, a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted; or R.sup.1 and R.sup.2, together with the adjacent nitrogen atom, may form a nitrogen-containing heterocyclic ring which may be substituted; or R.sup.2, together with the adjacent nitrogen atom and Y, may form a nitrogen-containing heterocyclic ring which may be substituted; or a salt thereof is useful as a preventive or therapeutic agent for obesity, etc.