Abstract: The protection mode of the literature covering paper books, microfilm and digital documents can head for a virtuous circle in literature protection.Experience has shown that it is the most effective method of literature protection.In order to promote the practical application of micrographic,we should use both the COM(Computer Output Microfilm)and the photomicrography technology at the same time.We should also construct the strategic balance of these two practical ways.And then,we can ensure the all-sidedness and coordination in the work of microform document conservation and preservation.

Key words: document microfilm technology；digital microfilm；digital to analog technology