The phrase Laixi originated from remote times, and Xilai appeared in the Ming Dynasty, which was rarely used in ancient times. But with its rapid development in modern times, its frequency of use even overtakes Laixi. Until the beginning of this century, the implement of Laixi and Xilai is still dominated by negative military aggression and natural disasters.However,they have some new usages paired with something neutral or even positive in recent years. Starting with diachronic development and rules of lexicalization, this paper will compare and differentiate these two terms from the semantics, structure,and pragmatic aspects in order to make further understanding of language rules of the vocabulary and grammar reflected by them. This thesis contains eight chapters.Chapter One is an introduction, methods, objectives, significance, literature review and research contents. Chapter Two sort out, analyze and then sum up diachronic development of those two terms from remote, medieval ancient, and late antiquity periods. Chapter Three is about Laixi and Xilai and lexicalization in modern Chinese, at the same time I make a detailed demonstration for evolution from phrases to words of Laixi and Xilai from the perspective of lexicalization, which draws out new semantic and structure characteristics that are showed in modern times.Chapter Four talks about semantic generalization of Laixi and Xilai and its causes.Chapter Five mainly refers to modern development and changes of these two terms in syntactic function.Chapter Six writes their styles and pragmatic values. And the last chapter is the conclusion, including the achievements and shortcomings of this study. And research findings answer those three issues raised in the introduction from different paragraphs.

“來襲”這一固定搭配起源於上古時期，“襲來”則出現于明朝，在古代罕有應用，但 是在現代卻發展迅速，使用頻率甚至反超“來襲”。 直到本世紀初，“來襲”和“襲來”的施事仍以消極色彩的軍事侵略、自然災害為主， 但是近些年來發展出與中性甚至積極色彩的事物搭配的新用法。本文將從歷時發展和詞彙化 規律入手，從語義、結構、語用等方面進行對比辨析，從而對其體現出的詞彙和語法等語言 規律進行更加全面深入的認識理解。 論文共分為八章，第一章是引言，交代了研究背景、研究方法、研究目的、研究意義、 研究綜述和研究內容。第二章分上古、中古和近古時期整理並分析總結了古代漢語中“來襲” 和“襲來”的歷時發展情況。第三章是現代漢語中的“來襲”、“襲來”及詞彙化。總結了 來襲在現代展現出的語義和結構的新特點，並從詞彙化角度對“來襲”和“襲來”從短語凝 固成詞進行詳細的論證。第四章是“來襲”和“襲來”的語義泛化及原因。第五章是“來襲” 與“襲來”的句法功能在現代的發展變化。第六章是“來襲”與“襲來”的風格特點及語用 價值。第七章是結語，總結了本文的研究成果和不足之處。研究成果分段回答了論文開頭引 言中提出的三個問題。