As a result of the investigation of the alkaloidal content of Corydalis rutifolia subsp. erdelii growing in Turkey. 25 alkaloids belonging to nine groups of isoquinoline skeleton have been isolated. Among them, sanguinarine and (+/-)-chelidimerine were determined as benzophenanthridine type. The occurrence of (+/-)-chelidimerine is the first report of a dimeric benzophenanthridine in Corydalis species.