Abstract: Due to the influence of geography, history, culture and social customs, English has divided into two major varieties: British English and American English, each having its own characteristic. The differences of American and British English vocabulary can be grouped into three categories：The same word having different meanings in these two countries, the same meaning expressed by different words in these two countries and the words that can be used only in one of the countries. But the concept of differences must not be taken too far, because British English and American English will be two major varieties of one language, not two different languages.

Key words: American English (AmE), British English (BrE), vocabulary, differences

摘要：英语是世界上运用最广泛和影响极大的语言之一。但由于地理、历史、文化、社会习俗等不同因素的影响,当今的英语已经演化成为最具有广泛影响的两种世界性的英语变体,那就是英国英语和美国英语。因为它们只是一种语言的两种主要变体而不是两种不同的语言，所以差别不是很大。英、美词汇差异主要有三种不同表现:同词异义,同义异词和特有词。关键词：英国英语，美国英语，词汇，差异