The objective of this research is to investigate whether the implementation of visualizing Media can increase students’ reading comprehension ability at the fourth grade students of Labschool Primary School Setiabudi South Jakarta. The strategy was applied by having students to draw their visualizations on the provided storyboarding worksheet while reading a simple text. This is the Classroom Action Research that was conducted in two cycles according the model of Kemmis and Taggart. This model describes into a spiral consist of planning, acting, observing, reflecting and replaning. Subject of this research were 22 fourth grader students from Labschool Primary School Setiabudi South Jakarta. The data were collected through test instrument to measure students’ level of reading comprehension. There was also record the activity of teacher and student in class to test the efficacy of visualizing strategy in a teaching environment including teacher and students’ activities. The instruments have been validated by expert judgement. The result of this research is a significant increase in reading comprehension ability score after the application of visualizing strategy. In cycle 1, percentage of students who scored ≥ 70 are only 63, 6% whereas in cycle 2 the score increased to 95,4%. The increment in students’ grade of reading comprehension ability is a direct result of the implementation of visualizing strategy’s efficacy which also increased from 65, 8% to 93, 3%.

reading comprehension ability, fourth grader student, visualizing media