In the early days after the opening, Japanese and Chinese books were classified by the Nippon Decimal Classification (NDC) and Western books were classified by the Universal Decimal Classification (UDC), based on the recommendations of the Downs Report.
図書の整理は、開館当初はダウンズ勧告に基づいて、和漢書は日本国内の図書館で一般的な日本十進分類法(NDC)、洋書は世界的に使われる国際十進分類法(UDC)によって行れていた。