Abstract: New amino-isoquinoline derivatives of the general formula: ##SPC1##Wherein R.sub.1 and R.sub.4 are the same or different and each represents a hydrogen or halogen atom or an alkyl group, R.sub.2 and R.sub.3 are the same or different and each represents a hydrogen or halogen atom or an alkyl or alkoxy group or R.sub.2 and R.sub.3 together represent a methylenedioxy radical, R.sub.5 represents a hydrogen atom or an alkyl or aryl group and R.sub.6 represents a di (lower alkyl) amino group or a nitrogen containing 5- or 6-membered heterocyclic radical linked to the isoquinoline nucleus either through a carbon atom or through the nitrogen atom such as 2-, 3- or 4-pyridyl, or 1-pyrrolidinyl are described. The aforesaid alkyl and alkoxy groups are preferably lower alkyl and lower alkoxy groups respectively. By the terms "lower alkyl" and "lower alkoxy" as used in this specification are meant straight or branched chain alkyl and alkoxy groups respectively having at most 6 carbon atoms.