A very unique case is found in the architectural remains related to the north and south square-platform at the lecture hall site of Hwangnyongsa, that of Anyangsa, and the estimated lecture hall site of Beopsusa as they are not observed in the other lecture halls. The platform has been discovered at only those three Buddhist temples from Goryeo, and its case has not been found in ancient Buddhist temples of China and Japan. This study thus set out to investigate the north and south square-platform at lecture hall sites by examining in details its architectural remains at the three Buddhist temples and reviewing the Buddhist literature about the lecture halls of ancient Buddhist temples. Based on the findings, it was estimated that the architectural remains of north and south square-platform at the lecture hall sites of Buddhist temples were those of platform for Buddhist sermons or those of high chair platform. While the north square-platform involved the remains of north high chair for the Lecturer that gave lectures on the Buddhist scriptures, the south one did those of south high chair for the Reader who recited the Buddhist scriptures.