Dialects in the north part of Shanxi belong to Jin Group, which are distributed over 26 counties in the northern and middle part of Shanxi Province. This thesis aims to have a comprehensive and systematic study of phonology in the north part of Shanxi Dialects, based on the materials we collected and the materials published. Firstly, we describe the general situation of phonology in the north part of Shanxi dialects briefly, and then place an emphasis on describing, analyzing some important phonological phenomena, such as tone sandhi, colloquial-literary strata, "biandu " and etc. In terms of the historical phonology, we analyze the changes of finals, including changes of vowel-ending finals, nasal-ending finals, stop-ending finals, and changes of medial, trying to explore the clues of diachronic development form the synchronic types. We also contrast phonology of Shanxi Dialects in the north part with that of its neighbors and find that dialects in the north part of Shanxi retain the most important feature of Jin Group, on the other hand, the features of Jin group in the dialects of the north part of Shanxi are gradually eroded under the impact of Putonghua. owing to its location being far away from the center of Jin Group. dedecms.com