The aim of this study was to know the vocabulary levels of Junior High School and Senior High School English Textbook, the number of words that students should be attain the 95% comprehension, and the percentage of the words in JHS and SHS English textbooks. The method of this study used descriptive method. The technique of data collection was only documents of JHS and SHS English books. The instrument of this study was a program based computer. It was Web VocabProfiler program. The research‟s results showed that vocabulary levels in JHS and SHS textbook were the 8,000-word level covers only 96.17% of the words in JHS English textbook and 96% of the words in SHS English textbook. The number of words that students should be attained for 95% comprehension passed the 2,000 word level. In JHS English textbook required students to know 329 new word families or 8.56% of the total tokens in the text, while SHS English textbook required students to know 611 new words families or 12.14% of the total tokens in the text. However, SHS English textbook contain more interdiciplinary academic words in Coxhead‟s AWL, where they contain 3,65% while the JHS contain 1,76% of the tokens in the texts.