Vocabulary learning has been regarded as a crucial part of second language learning andteaching. Therefore, it is essential for language teachers to pay great attention to vocabularylearning. The purpose of this research is to investigate and seek what aspects of vocabularyknowledge the three countries’ middle school English textbooks focus on. Besides, it aims todiscover whether the East Asian countries’ middle school English textbooks put little attentionson some aspects of vocabulary knowledge as the international English textbooks do. Thesignificance of this study is trying to fulfill the gap that few studies are conducted in examiningthe aspects of vocabulary knowledge and try to give the teachers, students, and textbook writersone direction on how to learn vocabulary. Three research questions are designed in this study. The first research question is “Whataspects of vocabulary knowledge do Chinese middle school English textbook vocabularyactivities focus on?” And the second research question is “Do Chinese middle school Englishtextbooks focus on different aspects of vocabulary knowledge from the Korean and Japanesemiddle school English textbooks?” The third research question is “Do middle school Englishtextbooks focus on different aspects of vocabulary knowledge, in different school years, withineach country?” Eleven English textbooks are examined in this study: three Korean English textbooks namedMiddle school English (MSE); five Chinese English textbooks called Go For It (GFI); threeJapanese English textbooks named New Horizon (NH). The research employed the textbookquantitative content analysis research method to compare the three countries’ textbooks. The research results show that textbooks from all three countries put the form and meaningas the most important aspect to learn in the textbooks. Besides, the associations, the constrainson use, and the word parts are the aspects receiving little or even no attention, which findingsare similar to Brown’s (2010) research results on international English textbooks. In other words,the East Asian countries’ textbooks are in line with the design of international English textbookson the vocabulary knowledge. Thus, this study suggests that a more rounded view of vocabularyknowledge needs to be adopted by Chinese material or textbook writers.