Adopted innovative methodologies in teaching reading comprehension have been a topic of interest by reading scholars among which textual awareness raising seems to be effective in the reading classroom. Following this, the present study looked into the effect of reading instruction by raising the students' awareness of different expository text structures on their reading comprehension ability. The sample of the study was selected from the undergraduate EFL students in Islamic Azad University, Guilan Branch, Roudbar, Iran. In this regard, the students of two intact classes took part in Oxford Quick Placement Test (OQPT) and 60 students (30 in each class) who reached the criterion of upper-intermediate were considered as the participants of the study. Then, the classes were randomly assigned into the experimental and control groups. The reading comprehension pre- and post-tests were utilized before and after the treatment in the data collection procedures. The treatment sessions aimed to raise the learners' awareness of the variety of structures used in expository texts. Results of the inferential statistics revealed a significant mean difference between the reading comprehension of the experimental and control groups after the treatment. It was found that raising the students' awareness of text structure by adopting different expository texts resulted in the improvement of students' reading comprehension ability in the experimental group. Findings can contribute to the practical application of raising the students' textual awareness as an effective strategy in assisting them to get mastery over reading comprehension skill.