The purpose of this study is to investigate the effects of the reading intervention using self-monitoring strategy and behavior modification principle on reading comprehension of children with Attention-Deficit Hyperactivity Disorder(ADHD) and poor reading ability. Children with ADHD have difficulty in reading comprehension due to deficiency of working memory and executive function, as well as behavioral characteristics such as inattention, impulsivity and hyperactivity. Therefore, this study intended to structure reading intervention and examine its effects by applying behavior modification principle for self-monitoring strategy and motivating, which belong to metacognitive strategies in the reading process. For the purpose of this, this study conducted single subject research based on multiple probe design across paricipants, oriented to three children with ADHD who are in the lower grades of the elementary school. The intervention applied self-monitoring strategy of the reading process in company with behavior modification principle. Self-monitoring constituted the program allowing not only the review of the understanding of self-performance and the content of text in the reading process, but also the learning of how to grasp the main content. Moreover, it defined target behavior to incorporate behavior modification method into the intervention process with consistency. The precision level of reading comprehension of the research participants was measured by the test of reading comprehension developed my me in quality of researcher. This test inquired into the changes of level of reading comprehension through the stages of baseline, intervention and maintenance. The research results show that the research participants improved the precision of reading comprehension after the intervention participation and the effects continued even 4 weeks after the termination of the intervention. Based on the results, the fundament of effectiveness of the intervention of this study was discussed focused on the characteristics of children with ADHD, and this study proposed considerations for follow-up studies.