The present study is a review of the cases of 25 patients who allowed to enter this hospital for further evaluation and diagnosed Scalenus Syndrome from '68 Nov. to '70 Oct.We classified under the following three type; vascular type, neurological type and combined type.1. In angiography, the stenosis or obstruction was observed in vascular type, but, no stenosis was observed in neurological type.2. In motor and sensory nerve action potential the delay of velocity motor nerves and sensory nerves could not be observed, but the amplitude of sensory nerves decreased in 2 cases with neurological and combined type.3. The autonomic nerve system test was showed abnormality in 8 cases of 10.4. Allen test was of no value as diagnostic test. Adson test was seen in 50% patients positive and Halstead test was 70% positive.