This research attempts to investigate grammatical and lexical cohesive devices employed in successful IELTS task 2 essays and offers suggestions to enhance learning and teaching practice for ielts writting skill. Data for the study are primarily collected from operational versions of ielts practice test books (Cambridge University Press) and some websites such as www.cmabrigeenglish.org, www.ieltsliz.com, www.ielts-blog.com. Methodological approaches employed in the study include both quantitative and qualitative methods within a mixed-method paradigm. In the findings and discussion, we have focused on discussing grammatical and lexical cohesiveness of IELTS writing task 2 essays on band score from 7 to 8. Various sub types of cohesive devices were found in these essays. It is hoped that results of the study bear beneficial implications for both teachers and students.