Academic writing is an activity to fulfill a requirement of college, university, conference, and publication. Of many types of academic writing, an essay is the most popular one, and an argumentative essay kind of the basic type of essay. The purpose of this study is to investigate the extent to which students compose their argumentative essays in essay writing class by considering the cohesion and coherence of their writing for Indonesian English as a Foreign Language (EFL) students. The theory used in this study was Halliday and Hasan’s (1976) “Cohesion in English”. Systemic Functional Linguistics (SFL) was applied as the approach. The study used qualitative descriptive methods. Ten essays were randomly selected from a total of 52 students' argumentative essays. The results showed that the use of references, ellipsis, substitution, conjunction, and lexical cohesion was still problematic. The findings also found that mostly the students used references more in order to refers back to someone or something that has been previously identified. It implicated that coherence analysis found that some students still need to pay attention to each word selection and the continuation of each paragraph. However, EFL students’ need more practice to form coherent sentences and paragraphs.

Keywords: argumentative essay, coherence, cohesion, writing class