本文有兩個主旨，一個在於試用一個新的研究方法，一個在於研究入聲舒化的路 線。在中國大陸有兩個大工程在山西方言的研究報告。兩份報告在聲調的類別與音值兩方面 往往都有不小的出入，而調查進行的時間相距約有二三十年之差。作者認為期間的差別可能 反映了不同年齡層之間的差異或是正在進行中的變化。這是利用現時的、當代的資料透視歷 史發展痕跡的嘗試。 在101個方言點�堙A有88個方言都有一個近似53值的降調；其間又有87%是出現於 去聲或上聲。本文討論的是南區24個方言，在這些方言�堙A去聲與上聲常有此一降調，而 去聲又常出現在調類界限模糊或有所重疊之處。上述的情況顯示去聲處於一個樞紐性的地 位。作者比較兩份資料�堛漁t異推測聲調演變的路線。所得的結論是在這些方言�堙A入聲最 初舒化時先變為去聲，然後才併入其他聲調，而變化的進行往往發生在一個高降調上。此處 入聲先變為去聲的舒化路線與中古音之前入聲舒化的路線相似。

　　　　　The main issue addressed in this paper on the southern sub-group of Shan-Xi Mandarin dialects lies with an identification of a 'Qu-centrality' mode of Ru-sheng transitions. Also put under scrutiny is a high-falling pitch 53, its shifting between the tonal categories of Shang and Qu in the great majority of the 101 dialects of Shan-Xi as well as its prominent presence at the junction of most cases of border disputes between tones. This paper makes use of two studies, Hou et al. 1986 (field work started in 1957) and Hou et al. 1993 (field work started in 1986) which often contain differently described pitch values and differently classified tonal categories for the same dialects. Such inconsistencies are viewed as reflecting changes in progression, in this way, historical perspectives have been discerned from synchronic data that are separated by a space of 2 to 3 decades. Thus, this study is a methodological attempt to handle differently reported information on the same dialects with a view to exploring historical information from synchronic data.