With IELTS’s worldwide recognition as an accountable indicator of English proficiency level, scholars have investigated IELTS extensively to provide insights for ESL teaching. Despite the manifold investigation into the validity, typographical features, washback on candidates and practical knowledge of the reading test, little research is done to manifest its lexical cohesion patterns and pedagogical implications. To fill in the research gap, the researcher selected 20 natural science passages from IELTS reading passages and conducted textual analysis under Halliday and Hasan’s English cohesion framework. Pedagogical implications are revealed by combining research findings with a lexical-based teaching approach, lexical syllabus design and knowledge structure development in the subject matter. Research findings indicate that the lexical cohesion patterns of natural science passages share similar organisational structures with subject matter knowledge. Reiteration patterns establish a panoramic view and taxonomic framework of subject matter, whereas collocation patterns focus on detailed explanations, examples and contextual extension that can contribute to the accruement of real-world knowledge. Based on these findings, the study suggests that the teacher can integrate lexical cohesion syllabus into the traditional pre-reading, while-reading and post-reading teaching stages. Though limited in scope and validity, these findings can provide a framework of combined research between text analysis and teaching approaches. More empirical experiments can be followed up to undergird the efficacy of the suggested lexical syllabus and provide more detailed pedagogical insights.