The invention discloses quinoxaline derivatives or salts thereof having PDE9-inhibiting activity and being useful as treating agent of dysuria and the like, which are represented by the formula (I) in the formula, R 1 and R 2 each independently stands for hydrogen, halogen, alkyl, alkoxy, acyl, amino and the like, R 3 stands for alkyl, aryl, saturated carbocyclic group, saturated heterocyclic group, acyl and the like, R 4 stands for hydrogen, hydroxy, alkyl or amino, R 5 and R 8 each independently stands for hydrogen, halogen, alkyl, alkenyl, alkoxy, cyano or nitro, R 6 and R 7 each independently stands for hydrogen, halogen, alkyl, alkenyl, alkynyl, alkoxy, cyano, amino, carbocyclic group, heterocyclic group, COR 9 or SO 2 R 9 , R 9 stands for hydrogen, hydroxy, alkyl, amino, pyrrolidin-1-yl, piperidin-1-yl, pyperazin-1-yl or the like, X stands for S or O, and A 1 , A 2 and A 3 each independently stands for N or C.
