Qianjin Yaofang by Sun Simiao of the Tang Dynasty is a comprehensive collection of medical classics. The original version has been lost. Zhenben Qianjinfang, as the earliest extant version, contains a large number of common characters and has a very high reference value. This article takes the common characters in Zhenben Qianjinfang as the object of investigation, and uses research methods such as document collation, Chinese character studies, and exegesis to comprehensively sort out and systematically describe the common characters in the book, in order to provide reference for the study of ancient medical books. Based on preliminary statistics, there are a total of 661 pairs of characters that have a relationship between orthodox and secular in Zhenben Qianjinfang. Referring to Mr. Zhang Yongquan’s classification method of vulgar characters, these vulgar characters can be divided into nine categories, including changing meanings, changing sound symbols, simplification of glyphs, multiplication of glyphs, writing variation, splitting or merging of components, displacement of components, newly created vulgar characters, and borrowing pronunciation and common words, etc. For each type of common characters, typical examples are cited for critical analysis to explain the formation mechanism and rationale behind the glyphs of the common characters. To sum up, the formation of the common characters in Zhenben Qianjinfang is mainly the result of the combined effects of two internal and external factors. The evolution of glyphs, the need for semantic expression, and the phonetic characteristics of Chinese characters have contributed to the emergence of vulgar characters within the language system, while external factors such as politics, technology, and culture have also had a certain impact on the formation of common characters.

Pei Songzhi (Year 372-451)’s annotations on The History of the Three Kingdoms have greatly revised, improved and enriched the original content of The History of the Three Kingdoms written by Chen Shou. The linguistics and philology value of Pei’s annotations are remarkable, which are reflected in the following three aspects. Firstly, in terms of phonetics, there are 99 phonetic notations (for 96 Chinese characters) in The History of the Three Kingdoms, and the methods are mainly Zhiyin (including "Yinru") and Fanqie, moreover they reflect the phonetic characteristics from the Later Han Dynasty to the Eastern Jin Dynasty. Secondly, there are 98 lexical annotations in total, producing new words and new meanings, and most of them are still used by later generations. Lastly, there are 39 philology annotations. Pei Songzhi annotated the rare and incomprehensible characters in the text, and also listed many opinions for reference. Additionally, Pei Songzhi attached importance to the influence of glyphs on the meanings of Chinese characters, and focused on analyzing words and textual meanings from the perspective of philology. Pei Songzhi’s annotations are concise and clear, meticulous and rigorous, and also express his own views and opinions, with distinct personal characteristics. Pei’s annotations on The History of the Three Kingdoms have profound research value and significance in linguistics and philology, which are worthy to be carefully explored, and the results will play an important role in enriching the research content of the history of Chinese language.

“Yu (于)” and “Yu (於)” both exist in The History of the Three Kingdoms, while the frequency of usages are different, with same and different usages. This paper takes The History of the Three Kingdoms During Shaoxi Period of Song Dynasty (The Twenty-Four Histories in Collection of Various Editions) as the research material, and investigates the usages of the words “Yu (于)” and “Yu (於)” in it, also referring to the other three editions of The History of the Three Kingdoms and checking each other to clarify the words and usages. In The History of the Three Kingdoms, “Yu (於)” appears 4544 times, “Yu (于)” appears 861 times, and the usage ratio is 5.28:1. “Yu (於)” is more widely and frequently used than “Yu (于)”. These two words are used most abundantly as prepositions. The prepositions “Yu (于)” and “Yu (於)” can both guide the complements of time and place, as well as elicit action objects and express passiveness. Additionally, in the three pairs of common phrases, the usages and meanings of the corresponding words are same. The difference is that the preposition “Yu (於)” has more plentiful usages and fixed usages of “Yushi (於是)” and “Zaiyu (在於)”, moreover, “Yu (於)” is often used after war verbs, and “Yu (于)” is rarely used. Furthermore, “Yu (於)” can be used as an interjection, and “Yu (于)” in proper nouns cannot be written as “Yu (於)”. It can be seen that, different from the pre-Qin period, the grammatical function of “Yu (於)” in The History of the Three Kingdoms is much stronger than that of “Yu (于)”, which reflects the trend that the weakening of the usages of “Yu (于)” in the Wei, Jin, Southern and Northern Dynasties, while the function of “Yu (於)” is gradually becoming stronger. Besides, there are many usages preserved through “Yu (於)” from ancient Chinese to modern Chinese.