The purpose of this study was to verify the effect of reading strategy intervention using the single ladder graphic organizer, integrated graphic organizer developed by the authors on the summarization of explanatory text and reading attitude of students with poor learning in middle school. The subjects of this study were students with poor learning in second grade of B middle school located in A metropolitan city. There were 8 students each in the experimental and control group, and the experimental group had 16 interventions twice a week for 8 weeks at 45 minutes each. As a result of the Mann-Whitney U test on the post-test scores of the two groups after the intervention, it was confirmed that the reading summary score of the experimental group was significantly improved compared to the control group in all three sub-domains of discrimination, coherence, content expression as well as the overall score. It was also confirmed that the reading attitude was significantly improved compared to the control group in all sub-domains of overall attitude, reading belief, and reading behavior in addition to the overall score. Accordingly, the researcher provided a discussion and suggestions for follow-up studies, focusing on the results of the independent variable on the dependent variable and the possibility of using the single ladder graphic organizer, an integrated graphic organizer.