The foreign literature on restoration thought and understand the essential meaning of intervention level. Furthermore, compare the connotation of restoration standards in the US, Japan, China, and Taiwan; so that, to be the basis for examining the substantive restoration content in the future. The summary is: «the Standards for Rehabilitation» and «the Standards for Restoration of the US» are brief, pointed, and essentialized. In addition, the each instance of «the Guidelines for Rehabilitating Historic Buildings» is easy, clear, cogent, and demarcated. On the contrary, the standards in Japan, China, and Taiwan, are without clear expression corresponded one by one. Therefore, this study takes «the Standards for Rehabilitation and the Guidelines for Rehabilitating Historic Buildings» as discussion basis on the historic restoration thought of the Former Tainan Prefectural Hall.