本文以韩礼德的系统功能语法理论为基础,以中美两国例行记者会实录为语料,主要从情态的角度对中美新闻发言人话语中的人际意义进行对比分析,旨在揭示中美新闻发言人在运用情态表达人际功能方面的异同,并试图从文化角度对情态词的使用差异作出阐释,以期对中美外交话语有更深的理解。研究发现,由于中美两国各自的文化价值观不同,中方新闻发言人在回答记者问题时多使用高量值情态词,美方则多使用中低量值情态词,分别表达了不同的人际意义。 Based on Halliday’s system functional grammar theory, this article takes the record of the routine press conference between China and the United States as the corpus, and compares the interpersonal meaning of Sino-U.S. Spokesman’s discourse mainly from the modality point of view. The spokesman used the modality to express the similarities and differences of interpersonal functions, and tried to interpret the differences in the use of modal words from a cultural point of view in order to have a deeper understanding of Sino-American diplomatic discourse. The study found that due to the different cultural values ​​of China and the United States, Chinese press spokesmen used more high-value modalities in answering press questions. The United States used more middle-low modal modalities to express different interpersonal meanings.