The main purpose of the present study was to investigate the effect of met cognitive strategies on reading comprehension among Jordanian university students. The participants of this research consists of two classes of English Course , Level one with 60 students, 30 in the control group and 30 in the experimental group. Then, Metacognitive reading strategies instructions were administered to identify their met cognitive strategy awareness. The experimental group underwent a treatment based on Chamot and Rubin (1994) model, while control group did not receive any strategy-based treatment The students were belong to Faculty of Arts and Educational Sciences, Department of English Language and Literature .All students were considered as low proficiency in English language due to their scores obtained in the English language placement test conducted by the university at the beginning of each academic year. To answer the question of the study, an achievement reading comprehension test is used as a pre-test and a post-test to both: the experimental and the control group with some modification related to the ways each group is taught accordingly. A multiple-choice reading comprehension test of twenty questions is constructed to assess the students' comprehension of the reading text. Proper statistical analyses were used to analyze the results. For the purpose of the study, the scores of control and experimental group were compared at the end of instruction period. The results revealed that the post-test scores of the experimental group were significantly higher than those of the control group. These results prove that the teaching on the basis of the metacognitive strategies instructions was successful to develop the students' ability to learn vocabulary.