本文以斯宾塞(J.Spencer)和格里高利(M.Gregory)语言理论为基石,着重研究语域构成三概念中话语范围与话语基调之间的关系,通过对同时代的雪莱、狄更斯以及哈代所写的三封家信的分析,较充分地说明了以话题为核心的话语范围对以正式度为体现的话语基调具有重要的制约作用。 Based on the language theory of J. Spencer and M. Gregory, this dissertation focuses on the relationship between discourse scope and discourse tone in the three conceptions of the formation of the register. By referring to the contemporary Shelley, The analysis of the three letters written by Charles Dickinson and Hardy fully illustrates that the scope of the discourse centered on the topic plays an important role in restricting the discourse tone formalized.