Abstract: The testing form of English vocabulary is divided into "Vocabulary Breadth Measures" and "Assessment of the Depth of Vocabulary Knowledge". And "Vocabulary Breadth Measures" is widely used nowadays. But this method of testing only tests passive vocabulary of written English. Its result can not indicate the depth of the micro-study of vocabulary. Researchers abroad advanced the theory of "Assessment of the Depth of Vocabulary Knowledge", which is of great importance to the vocabulary acquisition of Chinese English learners.