AbstractFerdinand de Saussure and his theory have profound influence in the development of modern linguistics, especially in the establishment of structuralism. The core of structuralism is binary opposition. On the basis of Saussures book Course in General Linguistics, this paper tries to investigate the pairs of binary opposition, including its history, and the application of it in Saussures theory such as langue and parole, the signifier and the signified and synchronic linguistics and diachronic linguistics.Key Words: Saussure; binary opposition; structuralismChapter I. IntroductionFerdinand de Saussure plays an important role in the development of modern linguistics. The linguistic theories and research methods raised in his work Course in General Linguisftoircmsed the system and traditions of modern linguistics, which have profound influence in the linguistic field. In Saussure s mind, language is a system of arbitary vocal symbols used for human communication. In his book, Saussure studies the language image and language roles with the method of binary opposition. This paper tries to expound the binary opposition method in Saussure s linguistic theory, including the very beginning of its origin and its application. In addition, related studies and comments will also be discussed in the paper.Chapter II. Literature reviewAt the beginning, binary opposition appears as an important philosophical thought. Later, it is used by Saussure to demonstrate the linguistics rules. Because of Saussures promotion, it is widely used in many fields now. This chapter will illustrate the very beginning of the binary opposition and the pairs of binary opposition in Saussures theory. A. The origin of binary oppositionBinary opposition in the western philosophy can be traced back to the ancient greek time. A great amount of theories of Plato and Aristotle are based on the binary opposition thought, such as the material and the spiritual, existence and consciousness, form and content. After years of development, with joint efforts of Descartes, Rock, Rousseau, Voltaire and others, binary opposition has become an important method in modern western philosophy.B. Binary oppositions in Saussures linguistic theoryThe binary opposition theory in Saussure s book is inheritance and development of western philosophy. In Saussures mind, language is a social phenomenon which is unique to human beings. What s more, the study of language should use scientific methods just like the study of science. Therefore, he uses binary opposition and other scientific ways to study the linguistic. His famous binary oppositions include langue and parole, the signifier and the signified, and synchronic linguistics and diachronic linguistics.1. Langue and paroleScientific research should establish the object of study at the beginning. However, at Saussures time, language research still uses the historical comparison method. Then Saussure puts forward his view: other science could working after deciding the object, then other work can continue. In our field, things are different. (Saussure 9). Therefore, before Saussure decides the object of linguistic research, he distinguishes the two concepts of “langue” and “parole” first, then the object of“langue” is decided.Saussure believes that “langue” is the most important research object of linguistics (Daniele 322). He said, langue is the research object of linguistics and a systematic structure which is different from “parole”, a kind of personal conversation behavior (Saussure 137). Langue exists because of the universal agreement by all the members of the society. It is the most important part of the parole activities. Langue is also a symbolic system to express ideas (Wang 183). Whats more, langue is a kind of symbol in nature, a kind of mechanism existing in the human brain. Through these theories, Saussure defines the research object of linguistics, and began to use the scientific method to study other principles. He establishes the synchronic and the synchronic linguistics. In the synchronic mode, he uses the systematic method and binary opposition to determine disciplines of langue and parole. This disclosure provides a scientific method for the study of linguistics.2. The signifier and the signifiedThis is another important pair of binary opposition in Saussures book. Language is the combination of concept and sound rather than simply a combination of physical and name (Wang 183). In the symbol theory proposed by Saussure, the voice becomes the “signifier” part, and the concept becomes the “signified” part. In this pair of binary opposition, Saussure points out two principles: arbitrariness and line features.The signifier and the signified represent two categories in linguistic field. Thesignifier, with sound image as the element,representsa kindof reality,while the signified represents a possibility.It is worthnotingthat because of