Abstract: Extended units of meaning is an important theoretical and analytical term in Corpus Linguistics.However, in description, nodes have been assumed to be fixed and unchanging, and no semantic analysis of grammatical words has been carried out, which limits the research scope of extended units of meaning and needs to be re-examined.Using the Corpus of Contemporary American English, this paper extends the description of lexical, grammatical, semantic aspects around a node; then the inter-collocational analysis is adopted to describe the extended units of meaning by changing the observation start of nodes and collocates respectively; finally, the local grammar patterns are described and the research application discussed.The results show that the multi-level co-selection of extended units of meaning is linked as a whole.There are variant forms of nodes under the influence of all co-selected elements.The analysis of the word in each position presents multiple relationships at the same time.The results of this study are of great value for phrase lexicography and automatic processing of extend units of meaning.