The on-line Twenty-five Historical Classics were based on the mainland's Zhonghua Shuju editions, which are regarded as the most authoritative. From the ancient Historical Records to the Qing dynasty histories, passages are grouped in various categories, such as imperial biography, local affairs, chronologies, biographies of commoners, etc. The collection is nearly 40 million characters all told.
二十五史採用的是堪稱最具權威的大陸中華書局版本，從史記到清史稿，每本書大致按照本紀、志、表、列傳、後人註釋、相關附錄順序排列，共近四千萬字。