This study aims at defining the concrete content of micro- and macro- universal service in postal service through an exploration on the concept of universal service, and at the same time, achieving an understanding of the security methods for postal universal service adopted by means of exploration on experiences from Germany, France and England, etc., and status of Japan while other countries face the reformation of liberalization and privatization for postal service. An analysis on overseas reformation experience from a perspective of universal service security has led to three points for our reference as follows: first, concretion and legalization for the concept of universal service; second, partial liberalization and progressive freedom; third, an institution of postal universal service fund.