Abstract: Four patients with hypertensive encephalopathy, including two autopsies, were reported. From the clinical. and CT scanning data, it was suggested that brain edema might be an important factor in the pathogenesis of hypertensive encephalopathy. Pathological findings revealed marked congestion, serous leakage and diffuse petechial or punctate hemorrhages in various regions of the brain which was in favour of the above suggestions. According to such observations and also referring to Auer's experiments, the authors considered that cerebral vasodilatation (but not vasoconstriction) and secondary brain edema might be the pathogenetic basis for to produce hypertensive encephalopathy.