Abstract :
The study aimed to describe 1). What types of cohesive devices were used by the students in their abstract 2). How do the cohesive devices contribute to the cohesion of students? abstracts. This research used a qualitative method.
The data was collected through documentation of the theses written by undergraduate students. The researcher analyzed the data based on the theory of Halliday & Hasan (1976), which consists of four steps in conducting the data analysis - categorization, abstraction, coding the text, and describing the result.
The result showed that cohesion is shown in the text. There are grammatical cohesion and conjunction. The most dominant type of cohesion found is grammatical cohesion which consists of reference which occurs 146 times, conjunction 72 times, and ellipsis only appeared 1 time. While the Substitution does not appear. It can be concluded that the undergraduate students using the cohesive devices in their abstract which means they are competent in producing cohesion in their writing especially thesis?s abstract.