By integrating the online annotation system, Reading Annotator, a web-based annotation system for reading support, is developed to help students know how to read to enhance their reading abilities. Reading Annotator is expected to efficiently and effectively help students visual interactively make summaries to guide students analyze text structure by highlighting key elements of articles. Three different color highlight buttons, Topic sentence, Controlling idea, and Supporting detail, are developed to help students identify key elements of each paragraph so that students can get the gist of the text more easily and achieve better understanding toward the article. In addition to the three different color highlight buttons which are developed to help students identify key elements of each paragraph, the system also includes a supportive reading strategy button, Dictionary. By highlighting unknown words and click Dictionary button, students can look up these unknown words with the Yahoo online dictionary. Reading Annotator accommodates not only text structure, visual representations, and summarization reading comprehension strategies but also "reading to summarize". Moreover, by using the reading support to guide students to analyze article organizations by highlighting key elements so that "reading to analyze" can be accomplished.