This paper focuses on analyzing the causes that lead to the development of contemporary Chinese literature from the angle of philosophy of language, ie.making a theoretical study of how ancient Chinese literature changes to contemporary literature. the basic points inlude: language is not only a tool or signs,but also world outlook,thought and mode of thinking, which belong to two different levels;May 4th vernacular differs from ancient vernacular,as well as popular language;May 4th vernacular movement differs from the vernacular movement in late Qing Dynasty ang popular language movement in 1930's and 1940's;The change of language in May 4th literature is not only the change of the tool,but the change of thought;the ancient transformation of Chinese literature from Yin & Zhou Dynasties to Chun Qiu can be classified into the transformation from "pre-ancient Chinese" to ancient Chinese,and the modern transformation of Chinese literature in the period of May 4th can be classified into transformation from ancient Chinese to modern Chinese;there exists relationship of dissimilation and assimilation between translated literature and modern & contemporary Chinese literature;Hu Shi's view of language essence is basically the theory of the tool,and he hasn't distinguished the vernacular he advocated and traditional vernacular in essence,therefore, he hasn't recognized the profound relationships between the vernacular and literature revolution he advocated and the whole revolution of literature thought. The modernity of Lu Xun's thought and writings can be expounded profoundly from the viewpoint of language;as a language system,classiclal Chinese,with a great power,has influenced and assimslated Lu Xun's early writings about thought and culture,which makes them be traditional fundamentally; Impossibly to be Closed by Hu Shi and The Diary of a Madman embodied the two essencial principles for modern Chinese vernacular language and modern thought.