Known for his pioneering work in Chinese historical phonetics, Edwin Pulleyblank has compiled this Lexicon to present in convenient dictionary form the result of his researches on the phonology of Middle Chinese and its evolution to Mandarin.

The Lexicon complements Pulleyblank's earlier book, Middle Chinese, by providing reconstructed pronunciation for approximately 8,000 Chinese characters at three historical stages. Early Middle Chinese is the language of the Qieyun rhyme dictionary of AD 601, which codified the standard literary language of both North and South China the preceding period of division. Pulleyblank's reconstruction is a thorough reworking of that of Bernhard Karlgren, completed in the twenties, and in some respects differs radically from it. Late Middle Chinese is the standard language of the High Tang Dynasty, based on the dialect of the capital, Chang'an. It has not been reconstructed previously as a separate stage but is of special importance, since it is the ancestor of most modern dialects. Early Mandarin represents the speech of the Yuan capital, Dadu (present Beijing), around the year 1300, for which Pulleyblank's reconstruction differs considerably from that of Hugh M. Stimson. The sources and methods used in these reconstructions were fully discussed in Middle Chinese, but recent developments in phonological theory have led to some modifications in detail.

The entries are arranged alphabetically according to the Pinyin system with an index, by the traditional Kangxi radical and stroke numbers. The Morohashi number is also given for each character, enabling easy reference to this important Chinese thesaurus. Another useful feature of the Lexicon is the inclusion of the numbers in Karlgren's Grammata Seric