This research aims to analyze the most frequent academic words and also the collocated words that followed the most frequent academic word in students’ thesis at the English Language Education Program of Mulawarman University. The research adopted a quantitative method and used students’ thesis corpus as the only data. 33 theses that have been stored in 2021 were taken and analyzed with AntWordProfiler, AntConc, and TagAnt programs as instruments and standardized tools of measurement.

The findings showed that from the total 546 academic word families that appeared in the corpus data, there are 24 academic words were found as the most frequent academic words based on Coxhead (2000)’s Academic Word List (AWL) word selection criteria. Besides, this research also revealed that 47.89% of words that collocate the word Research as the most frequent word are from the Noun word class with 34 occurrences. It is suggested for students and educators consider the high frequency of academic words as the learning material to which they should pay attention in order to prepare for writing an academic paper.