The purposes of the research were as follows: 1) to develop online lessons on Computing Science  with cooperative learning techniques for Grade 5, Ban Chom Bueng School, 2) to assess the quality of the developed online lessons, 3) to find the academic achievements of students before and after learning with the online lessons  with cooperative learning management, and 4) to study the satisfaction of the learners towards the online lessons  with cooperative learning management. The sample group were 20 Grade 5 students at Ban Chom Bueng School 20. The tools used in the research were as follows: 1) the online lessons, 2) pretest, and posttest, and 3) the students’ satisfaction assessment forms. The statistics used in the data analysis were as follows: 1) mean, 2) standard deviation, and 3) t-test

         The research findings showed that 1) the online lessons assessed by 3 experts had the quality of the content at a high level which had the mean of 3.93 and the standard deviation of 0.90, and the quality of  the media production techniques at a high level which had the mean of 4.26 and the standard deviation of 0.86 , 2) the students' academic achievement after learning with the developed online lessons was statistically significantly higher than before learning at the 0.5 level, and 3) the students’ satisfaction assessment results was at a high level which had the mean of 4.97 and the standard deviation of 0.14.