The objectives of this research were 1) to develop online lesson cooperate with inquiry-based learning about Technology subjects (Computing Science) for mathayomsuksa 3 students, 2) to assess the quality of the content of online lesson about Technology subjects (Computing Science) for mathayomsuksa 3 students, and 3) to assess the technical and methodology quality of the of online lesson about Technology subjects (Computing Science) for mathayomsuksa 3 students. The target group were 8 content experts and 8 technical and method experts, obtained by purposive sampling based on the given qualifications. The tools used in the research were the learning management plan, online lesson content assessment form, and technical and methodological assessment form of online lesson. The statistics used in the research were mean and standard deviation.

            The results of the research showed that 1) online lesson cooperate with inquiry-based learning about Technology subjects (Computing Science) for mathayomsuksa 3 students consisted of 4 chapters and 4 lesson plans, 2) online lesson about Technology subjects (Computing Science) had the highest level of content quality (  = 4.79, S.D. = 0.24), and 3) online lesson about Technology subjects (Computing Science) had the highest level of the technical and method quality (  = 4.78, S.D. = 0.23).