This article aims to reconstruct the phonological system of Huìlín’s Yíqièjīngyīnyì’s Xièshè[蟹攝]. Huìlín’s Yíqièjīngyīnyì is a book of transitional period between Early Middle Chinese and Late Middle Chinese period. If you study the phonological system of this book, you can find that phonological changes between Early Middle Chinese and Late Middle Chinese period. Xièshè is selected as a research topic because Xièshè has a special rhyme that only have falling tone. Also Xièshè includes all of DivisionⅠ・Ⅱ・Ⅲ・Ⅳ.
We can find that Tàiyùn[泰韻] was merged with Hāi(Huī)yùn[咍(灰)韻], in Huìlín’s Yíqièjīngyīnyì. It means that ending –i raises the main vowel -ɑ to -ʌ. Also we can find that Guàiyùn[夬韻] was merged with Jiāyùn[佳韻] and Jiēyùn[皆韻] in Huìlín’s Yíqièjīngyīnyì. And it means that ending –i raises the main vowel -a to -ɛ.
Early Middle Chinse, there was no medial in DivisionⅣ. But in Huìlín’s Yíqièjīngyīnyì, it can be seen that medial was formed in DivisionⅣ. Fǎnqiè analysis, we can deduce that DivisionⅣ’s medial was similar with medial –j- that was medial of DivisionⅢ Chóngniǔ A, C1.