To provide a compound which has a potent agonisticactivity on GHS-R and which is useful as a therapeutic agentfor systemic wasting diseases such as cachexia.A 3,8-diaminotetrahydroquinoline derivative representedby formula (1a) (wherein X represents CH2, C=O, CH-OR, CH-SR,or CH-NRR'； m is a number of 1 or 2； Ar represents a phenylgroup, a naphthyl group, a 5-membered or 6-membered aromaticheterocyclic group having one or two elements selected from S,N, and O, or a similar group； R1 and R2, which may beidentical to or different from each other, each represent ahydrogen atom or a methyl group； R3 represents a C1 to C6alkyl group or a similar group； n is a number of 0 or 1； R4and R5, which may be identical to or different from eachother, each represent a hydrogen atom, or a C1 to C6 alkylgroup, etc.； and R6, R7, R, and R', which may be identical toor different from one another, each represent a hydrogen atomor a C1 to C6 alkyl group), or a salt thereof.(see formula 1a)
