Vocabulary is a collection of several words that are combined, so that they have meaning. Vocabulary test is a test to measure the ability in vocabulary. This study aims to investigate the aspects of vocabulary testing as well as the purpose of vocabulary testing. The design of this research is library research. The data was collected from literature review, such as books and articles. The data is then analyze using descriptive-deductive techniques, in which the researcher presents data on the aspects of vocabulary testing, namely the researcher presents data on the definition of vocabulary, aspects of vocabulary testing, and the purpose of vocabulary testing. Vocabulary teaching in English language teaching has several benefits. First, a strong vocabulary allows learners to understand reading, listening, and conversations better, as one expert, Wardani (2015), said that, "vocabulary is an important aspect of language, because it appears in every language skill, including listening, speaking, reading, and writing skills. It is important for English teachers to give sufficient attention to vocabulary teaching and develop appropriate teaching strategies to facilitate learners' vocabulary development. The results of this study show that learning is more effective and provides knowledge on how to answer vocabulary tests properly. The purpose of vocabulary testing is to find students' progress in vocabulary, measure how much vocabulary students know, find students' difficulties in learning, and help students become familiar with vocabulary.