Low reading interest and autonomous learning among elementary students are challenges in learning the Indonesian language. This study aimed to develop, validate, and measure the effectiveness of a picture story E-Book to enhance autonomous learning and reading interest among third-grade students at elementary school. The research applied the Research and Development (R&D) method using the ADDIE model, involving three experts (content, instructional design, and media) and 24 students as 24 students as effectiveness subjects, 3 students for individual trials, and 9 students for small group trials. Data analysis was conducted using descriptive quantitative and inferential methods. Data analysis was conducted using descriptive quantitative and inferential methods. Data were collected using multiple-choice tests, questionnaires, interviews, and observations. Validation results showed very good categories, with scores of 94.79% for content, 100% for instructional design, and 92.50% for media. The effectiveness test used a paired sample t-test, showing tcount = 12.243 > ttable = 2.069 at a 5% significance level, indicating a significant difference before and after using the E-Book. The study concluded that the picture story E-Book effectively enhanced students' reading interest and autonomous learning. The study's implications support the development of innovative technology-based learning to improving Indonesian language learning.