The author discusses the decreasing cause of the tone in Xinjiang Chinese dialect, based on deep language contact with Turkic Languages, especially the influence of Uighur language, the second import inter-communicative tool in Xinjiang.

• 摘要新疆汉语方言声调减少，不能仅从其内部找原因，还须结合语言接触史来进行探讨，尤其是区内第二大交际工具－维吾尔语为代表的突厥语族诸语言的影响不可忽视。