清代李汝珍（1763-1830）著有《李氏音鑑》（1805）一書，不僅介紹中國傳統音韻學（切音學）的聲、韻、調等問題，更透過頗大篇幅，深入討論反切與擊鼓射字之應用。筆者初步檢視《李氏音鑑》之後，發現李氏藉由歸納，將反切上下字進行整理，簡化反切所呈現的困難，更透過古代「空谷傳聲」原理，藉由符號歸納，建立「擊鼓射字法」，並在最後將例字、反切、擊鼓三次論通盤整理為〈字母五聲圖〉。

      本研究通過李汝珍《李氏音鑑》相關內容，探析李汝珍之音韻觀點，了解其所提之「反切」與中古反切之差異，並藉由「粗細」之定義與入聲字的「反切」改良探討《李氏音鑑》所反映的「反切」情況。此外，亦藉由空谷傳聲、擊鼓射字，探析「反切」與「擊鼓射字」間之關聯性。

         During the Qing dynasty, Li Ru-Zhen (1763-1830) wrote the book Li Shi Yin Jian (1805), which not only introduced the issues of sound, rhyme, and tone in traditional Chinese phonology (Qie-yin studies), but also extensively discussed the applications of “fanqie” and the “drumming and shooting characters” method. After a preliminary examination of Li Shi Yin Jian, the author discovered that Li Ru-Zhen organized the upper and lower characters of “fanqie” through induction, simplifying the diffi culties
presented by “fanqie”. Furthermore, by utilizing the ancient principle of “echoing in an empty valley”, Li Ru-Zhen established the “drumming and shooting characters” method through symbol induction. Finally, he compiled the example characters, “fanqie”, and drumming into a comprehensive “Five Tones Chart of Initials and Finals”.

        This study analyzes Li Ru-Zhen's views on phonology through the relevant content in Li Shi Yin Jian to understand the diff erences between his proposed “fanqie” and the Middle Chinese “fanqie”. By examining the defi nition of “thickness” and discussing the improvement of “fanqie” for entering tone characters, the study explores the situation of “fanqie” refl ected in Li Shi Yin Jian. Additionally, the study explores the relationship between “fanqie” and the “drumming and shooting characters” method through the principles of echoing in an empty valley and drumming.