The reflex changes of local hepatic blood flow (HBF) were studied in anaesthetized dogs. An increase of HBF following the acidification of duodenal mucosa and the injection of glucose solution into the intestinal lumen was demonstrated. An attempt was made to cast light on the underlying mechanism which may govern the above mentioned local circulatory reflexes in the liver, by investigating the effect of bilateral vagotomy and of the local anaesthesia of duodenal mucosa. The importance of these hepatic circulatory reflexes from the point of view of surgical indications and the clinical treatment is discussed.