In this paper described is how the Nippon Decimal Classification (NDC) became the national standard classification scheme in Japan. In the course of standardization the following three significant events are noticed.
1. The Classification Table of Yamaguchi Prefectural Library was approved as the national standard scheme in 1919.
2. The first edition of the NDC was published in 1929.
3. The Japan Library Association published the 6 th edition of the NDC in 1950.
The future of the NDC is discussed from the following view points: the revision policies for the 8th edition, the relation to the National Diet Library Classification Scheme, and the organization of the continuous revision system in order to maintain the NDC as the national standard sheme. The relationships between the Library of Congress Classification Scheme and the Dewey Decimal Classification are also described.
