Based on the review of “the Three Waves”of archives construction,the article sketches the evolution of archives functions expansion from the original serving our party and the government to the“Three-in-One”、“Four-in-One”and even“Five-in-One”. This thesis also analyses the reason of archives functions expansion and discusses the countermeasures to fulfill archives functions expansion which include updating our ideas guided by “the Scientific Outlook on Development”,creating modern images actively,improving the legal system taking the chance of the revision of the archives law,strengthening archives basic work,taking archives informatization construction as the breach to promote the integrated management and use of archival resources,and building a strong contingent of archival cadres.