The study on technological history of monument, that aims at clarifying technological problematic in monument restoration through discovering the history of “technology-in-use”. It would touch what is the question that study on technological history of monument? How to study the question? Precisely, it would refer to what is discursive formation of monument restoration? According to epistemology, because technological idea must establish on technology opposite the others, whatever “technology” or “restoration technology” both deeply concern with reflection about collective belief of society, and representation for imaged ideology of culture. Therefore, in order to re-clarify truth of monument conservation, that re-proposes the basic structure of technology in discourse of monument restoration, and re-establishing cognition of technological subjectivity about restoration technology. Consequently, the study constructs a methodology restoration by investigating concrete cases of monument restoration during 20~30 years in Taiwan and surveying information of field.