In order to analyse the origin and pathway of afferent connections to the ento-rhinal area(EA),the method of HRP have been used.Labeled neurons in the brainwere found in the contralateral EA,ipsilateral and contralateral parasubiculum andpresubiculum,claustrum,medial septal nucleus,diagonal band nucleus of Broca,reuniens of thalamus,superior central nucleus and locus ceruleus.Only the injectiondeposits which involved the lateral EA led to cell-labeling in the anterior pyriformcortex,dorsal raphe and ventral tegmental area.It is suggested that the EA canintegrate different kinds of information from very wide regions in the brain butthe neocortex.The presentstudy pays special attention to structures and someprobable functions of neuronal circuits between EA and other areas.