For the first time, the capillary space-bursa infracardiaca-which is present in human evolution, is investigated and described in reference to the pathogenesis of sliding hiatal hernia. This bursa at the right dorsal wall of the esophagus can obliterate, persist or even communicate with the bursa omentalis. It supports the cranially sliding movement of the gastroesophageal junction and reduces the slope posture of the plane of esophageal entry into the stomach. Extensive sliding movement permits the fat of omentum minus to develop a lipoma between the bursa and esophageal wall. With regard to the known specific muscle architecture of esophagus (Stelzner, 1968) the upward tilting of the plane of entry is followed by the opening of the cardia and by reflux. The bursa enlarges the postural change of the plane of entry. It can be considered as a disposing factor in the development of sliding hiatal hernia. This is evaluated by a lot of observations and with regard to former experiments.