Several studies have been done in order to find out the effect of formal instruction of conjunctions and references on reading comprehension of students. Research findings show that the presence of discourse markers makes it easy to comprehend a text. Most of the studies conducted have manipulated the text by adding or omitting discourse markers and examined the effect of the presence or absence of discourse markers on the reading comprehension. Khatib (2011) studied the relationship between knowledge of discourse markers and reading comprehension. He concluded that there is a high correlation between students' knowledge of DMs and their reading ability. Bahrami (1992) also studied the effect of the number of discourse markers in the texts on students' reading comprehension. He concluded that the group who took the test with the greatest number of DMs outperformed the other two groups. Akbarian (1998) examined the comprehension level of two groups with the same language ability, reading two versions of the same texts (original and manipulated ones whose DMs were deleted). The subjects who had the original texts, from which no DMs had been omitted, performed better. Innajih (2007) investigated the effect of explicit instruction of DMs on the reading comprehension of the second language learners.