Purpose: This study centers on the significant role of Reader Response theory in instruction literary text, this study also, affirms that there is a useful and progressive influence of the Reader-response strategy in the literary text to enhance and improve the level of EFL Iraqi learners’ critical thinking. This study proves that teaching literature, without Reader response strategies, the level of development of critical thinking becomes very passive and slow. Methodology: The researcher used one group “pre-post-test”. The study was conducted at the English department, Faculty of Education in Iraq. This study was carried out for fifteen weeks. The researcher administered Cornell Class-Reasoning Test as a pre-test in week 4 while post-test in week 12.The researcher used non-probability convenient sampling because it was probably the most common of all sampling techniques in social sciences and the proximity of the samples to the researchers (Patton, 1990).This test was run twice with intensive interventions for five weeks implemented between the two tests. Main Findings. Findings showed that there was a statistically significant difference in the EFL Iraqi learners' critical thinking skills between pre-test scores and post-test scores. There are statistically significant differences at the “p ≤ 0.05” level for the following item groups: 1, 2, 3, 4, 5, 6, 7, 8, 9, and 12. This study confirmed that participants significantly improved their level of critical thinking skills by implementing Reader- Response activities in teaching literary texts. Implications: This study proposes applying the strategies of reader-response theory as an effective and encouraging concept or stimulating approach to enhance the level of recognition and appreciation of the texts in literature. This experiment could be a positive study and applicable to different educational centers to teach all the texts in English literature. This study helps instructors to change their old-style manners of instructions. Novelty: The experiment focused on the vital and encouraging role of reader-response theory in fostering EFL Iraqi readers’ capacity to generate multi-layers of versions and meanings during reading literature. The study presents a helpful and successful manner to all the persons who work as teachers in educational systems. The study directs the instructors to follow the modern approaches in explaining the literary text to their learners instead of the old-style manner. EFL tutors should practice these strategies in EFL English classes of literature so that they could make the lecture full of activity and enjoyment throughout the interesting themes of literature.