本文的主旨在於探討政策論述在政策變遷過程中，所扮演的角色及地位。基本上，本文將政策變遷，視為是解構、建構及強化原本結構三股力量，在政策場域中相互運作的結果。而此三股力量，則往往具體地表現於政策過程中的行為者，所提出的各種論述之中。因此，本文認為，從政策論述的角度切入，是一個觀察及分析複雜政策變遷過程的可行途徑。本文亦建構政策變遷的四個類型：政策演化、政策工具、政策終止及政策成長，並分別探討它們各自的意涵及其受到各種流的影響。然而，本文認為政策論述的分析，不能只分析論述文本表面呈現的內容，而要從論述所鑲嵌的社會結構，政策場域中已提出的論述文本，論述者在政策網絡中所處的權力位置，被論述政策本身的發展及政策環境的演展情勢五方面，才能斷定論述所有權及主導權的歸屬，評估論述被接受的幅度，了解公共政策變遷的可能性、方向及內涵。

　　　　　The purpose of this article is to address the role and status of policy discourse in policy change. Basically, policy change is assumed to be the interactive effects of three streams of force: deconstruction, construction and strengthened original structure. These three streams of force are expressed by policy actors through policy discourses during the policy making process. Hence, the approach of policy discourse is a feasible way to observe and analyze the complexity of policy change. Another focus of this paper is to construct four basic types of policy change: policy evolution, policy succession, policy termination and policy growth. Then we turn the direction of analysis to the definition of each type of policy change and the impact of different streams on each of them. However, the analysis of policy discourse not only needs to focus on the content of discourse texts, it also needs to identify its embedded social structure, available texts, the position of discourser in policy networks, the policy itself and its contextual evolution. These five factors will determine discourse ownership and leading status and the magnitude of discourse acceptance. Moreover, they lead the possibilities, direction and implication of policy change.