As the second volume of a two-volume set on the history of Chinese phonology, this book studies the history of phonology from the Yuan dynasty until modern times and discusses the four approaches of sound change. Based on abundant phonological materials, the author divides the history of Chinese phonology into nine historical periods, which helps illuminate its evolutions and principles. Following on from the first volume, the first part of this second volume deals with the initials, rhymes, and tones of Chinese phonology from the Yuan dynasty (1279–1368) to modern times (since 1911), illustrating the diachronic sound changes with detailed tables. Based on an historical review of Chinese phonology, the second part of the book classifies sound changes via four major approaches: no change, gradual shift, split, and merger. It then analyzes the natural, conditional, and irregular sound changes, respectively, and the reasons for these changes. This title will be of great value for scholars and students studying Chinese phonology, Chinese linguistics, and readers interested in the essence of rhyming behind Chinese classic lyrics, poetry, drama, and other forms of verse.