Given that formulaic sequences play an important role in enhancing L2 learners' academic writing skills and that phraseological sequences constitute a large proportion of written discourse, the current study was an attempt to draw up a list of key phrase frames--phraseological sequences with a variable slot--in a corpus of research articles (RAs) in the field of environment. A complete list of such frames, extracted by kfNgram software, was subjected to a series of corpus statistics such as frequency, range, and keyness, as well as manual filtering. This resulted in the generation of 65 four-word and 20 five-word key phrase frames specific to the field of environment. Structural analysis revealed that the vast majority of these key phrase frames were content word sequences, while functionally most of them belonged to referential expressions. Pedagogically speaking, L2 learners are recommended to develop a rich repertoire of formulaic sequences such as key phrase frames which are considered the cornerstone of academic discourse.