In this study, I analyzed the system and the characteristics of GYLY by analysis of the examples referring to GYLY in the existing Buddhist texts. GYLY has been lost. This hampers our understanding of the system and the contents of the text, but we can assume its basic structure based on the references in KHYY, LKSJ, SXCDDZY, MFLHJSW, and other texts. Nothing is known about the exact date and hometown of Guo Yi, but sporadic information from some texts tell us that he is a contemporary of Xuan-ying and that he is a native of Hedong. GYLY existed by the 11th century in China, and it was transmitted to Japan where it was circulated by the 13th century at the latest. I analyzed a total of 650 examples in MFLHJSW, KJKOI, SXCDDZY, IMDSS, and STYK. GYLY takes the form of a dictionary book divided into 259 bu(部) based on the radicals. The text analyzes the Buddhist texts and describes the outlines of characters with regard to script, definition, and pronunciation.