最後，本研究分別對於教師教學應用與後續研究方向提出若干建議。 Reciprocal teaching is an instructional procedural to foster reading comprehension. The purpose of the study was to explore the effects of reciprocal teaching via asynchronous online discussion tool to improve reading comprehension in 8th graders’ class reading groups. The action research included two sections, (1) the researcher/teacher enacted the Explicit Teaching for Reciprocal teaching (ET-RT), (2) students used asynchronous online discussion tool and applied reciprocal teaching to read 8 assigned articles. 29 students (15 female and 14 male) were randomly assigned in group of three. Data collection included reading comprehension tests, worksheets, observations, video recording, interviews, and teachers’ reflection journals. The paired T test was used to analyze the reading comprehension exam scores. Worksheets, interviews, as well as teachers’ reflection journals, were analyzed qualitatively. The findings were described as below: 1.Students using reciprocal teaching and asynchronous online discussion improved reading comprehension ability significantly. 2.Students considered that abstract type of questions were most difficult, while prediction type were easier. 3.Students preffered via asynchronous online discussion to oral discussion and tended to consider that strategies were useful to reading comprehension. 4.The action research led the researcher to reflect on the strategies to facilitate small group discussion and to improve teachers’ knowledge and abilities to enact ET-RT. Finally, the research provided suggestions for future research and reveal issues for further clarification.