评价理论是在系统功能语言学三大元功能之一的人际功能基础上发展起来的。它由态度、介入和级差三方面组成,主要研究语篇中作者如何表达主观态度。本文从评价理论的态度子系统出发,对奥巴马出访古巴的演讲进行解读,分析奥巴马如何在出访演说中运用态度达到体现人际意义的目的,从而更进一步地揭示态度意义对于奥巴马出访演讲中的外交目的的体现具有重要作用。 The theory of evaluation is developed on the basis of interpersonal function, one of the three major functions of system functional linguistics. It consists of attitude, intervention and level of three components, the main text of the study of how to express the subjective attitude of the author. Based on the Attitudinal Subsystem of Evaluation Theory, this essay analyzes the speech of Obama on his visit to Cuba and analyzes how Obama uses his attitude in his visit speech to achieve the purpose of interpersonal meaning so as to further reveal the significance of attitude. For the diplomatic goal in Obama’s speech on his visit The embodiment of an important role.