This corpus-based research is aiming 1) to find out the word frequency which appears in the undergraduate thesis based on Coxhead's word selection criteria, 2) to find out the distribution of Coxhead's (2000) Academic Word List (AWL) in the undergraduate thesis in Indonesia particularly in Education field, and 3) to establish new academic words for undergraduate students in writing the undergraduate thesis. A 2.2-million-word corpus was compiled comprising 200 undergraduate theses deriving from 10 universities in Indonesia. The LancsBox 5.0 software was exerted to calculate the word frequency and percentage of the text by applying the quantitative method. By implementing Coxhead’s word selection criteria, only 1-million words appear more than 63 times in the undergraduate theses and at least appear 5 times from 5 universities. The research indicates that Coxhead’s AWL is as much as 8.95% and a new academic vocabulary is 4.46%. There are 268-word forms of AWL and 276 new academic vocabularies found in undergraduate theses. In sum, those words become an academic vocabulary for undergraduate students in writing an undergraduate thesis. Based on the findings of the results, it can be concluded that Coxhead’s academic word distribution in undergraduate theses of English education is still low compared with the distribution of AWL in other fields. Meanwhile, the new academic vocabulary in this study needs to be considered. It is essential to confirm that the use of the high-frequency word does not imply the inclusion of an academic vocabulary in writing undergraduate theses. This is because students rarely used low-frequency words. After all, they are unfamiliar with the words. Sometimes lowfrequency words are the words that have high frequency used by the experts in writing academic text. Therefore, the findings support the development of the new academic vocabulary by involving research articles and considering the unfamiliar words utilized by the students, but high frequency used by the native speakers or academicians in writing academic papers

Keywords : Academic Word List; New Academic Words; Corpus-based; Undergraduate Thesis.