The purpose of this study is to provide the methods of preservation for paper, microfilm, digital media. First of all, for acidic papers produced in 19~20 centuries, this study evaluates and analyses deterioration and factors causing deterioration. For book, also, environmental condition for preservation, and a preservation mechanism through acid-free procedure were suggested. Second for microfilm, it emphasized physical and chemical properties, oxidised substance during developing film, materials related to preservation. Third, for digital storages, storage conditions and needs, such as life-cycle and capacity were introduced.