Phase One study used qualitative data from interviews (N=20), observations (N=8), stimulated recall interviews (N=8), and assessment documents (N=8) to investigate teachers’ beliefs and practices about Chinese vocabulary teaching and their relationship. Based on the findings, questionnaires were developed and validated for the Phase Two quantitative study to further investigate teachers’ beliefs and practices, and their relationship (N=337). Phase Three study collected quantitative data from student tests (N=1228) to explore the effect of teachers’ vocabulary teaching on students’ achievement in vocabulary knowledge and reading comprehension.