摘要
This paper explores the intra-textual core vocabulary occurrence rates and core vocabulary growth patterns in the four sets of College English coursebooks favorably evaluated by the Ministry of Education of China in 2004. And the CECR (College English Curriculum Requirements) word list is adopted as the reference word list. The research result reveals that the single text occurrence rates of the core vocabulary of the four sets of books vary substantially from one to another, with New Horizon College English (INHCE) covering the most. In general, the vocabulary size steadily grows within the four sets of course books;however, the unsmooth vocabulary growth pattern does exist. And core vocabulary growth patterns vary due to the differences in the single text occurrence rates of the core vocabulary of the four sets of books.