Corpus-driven studies on lexical bundles (recurrent formulaic sequences) have provided us with valuable and useful information about different types and functions of lexical bundles in spoken as well as written registers. Recent research has examined patterns of the use of lexical bundles. Some of the previous studies have focused on the patterns of use of novice or student writers versus professional writers. Others have been focused on a comparison of L1 versus L2-English students. However, no study has compared the use of lexical bundles by L1-English versus L1-Farsi academic professionals. The present study fills this gap by analyzing the structural and functional features of lexical bundles applied by L1- English and L1-Farsi professional English writing in applied linguistics journals. The software AntConc 3.4.4., the instrument used in this study, identified four-word lexical bundles with the moderately high frequency of at least 40 and a range of occurrence in at least 20 different articles. 129 lexical bundles were found in the L2-English Corpus (L2-EC) and 86 in L1-English corpus (L1-EC). In order to analyze the structure of the identified lexical bundles, we classified them according to the taxonomy proposed by Biber,Johansson,Leech,Conrad and Finegan (1999). The functional framework chosen for this study was organized around three broad functional categories based on Hyland's functional taxonomy of bundles in academic writing (2008a, 2008b) (research oriented, text oriented, and participant oriented), with sub- categories grouping more specific roles.The results showed that both Native English and Iranian writers of English primarily used phrasal bundles (bundles consisting of noun and prepositional phrases) rather than clausal ones (bundles consisting of verbs and clause fragments), with native writers relying even more heavily on phrasal bundles. The two corpora also displayed similar proportions of the three main functional categories. Research-oriented bundles rank as the largest category in both L1-English and L2 English corpora, whereas participant-oriented bundles constituted the smallest proportion, with a higher percentage of native writers’ usage of these bundles. L1-F professionals used significantly fewer participant-oriented bundles than L1-E professionals did. In addition, the relationship between structural types and functional categories showed that L1 and L2 professionals employed bundles with different structural characteristics serving similar functions. Therefore, we can conclude that writers who majored in applied linguistics prove native like use of four-word lexical bundles, which could be due to their frequent exposure to English language during their academic education. Keywords: Academic articles, Applied Linguistics, Corpus, Function, Lexical bundles, Structure