The aim of this design-based-research study was to develop students’ conceptual understanding and engagement of electrochemistry course using an integration of technology mediated instruction Team-Pair-Solo method in Fitawirari Habtemariam Secondary school. The participants in this study were grade 10 students’ and they were chosen purposively. The data were gathered through classroom observation, pretest, posttest, classroom activities, interviews and focus group discussion and questionnaires. The students’ responses on the pretest, first cycle posttest and second cycle posttest were analyzed both quantitatively and qualitatively. The quantitative paired sample t-test showed that students’ were performed better in the second cycle posttest than the previous tests. A paired-sample t-test revealed that students’ scored significantly higher at the first cycle post-test (M= 13.37, SD= 2.35) compared to pre-test (M=7.93, SD=2.22), t (39) =11.103, p<0.01. Moreover, the second cycle paired-sample t-test revealed that students’ scored significantly higher at the second post-test (M=16.25, SD= 1.72) compared to the first cycle post-test (M= 13.37, SD= 2.35), t (39) = 6.57, p<0.01 indicating an improvement from cycles. The engagement questionnaire result revealed that students’ were highly engaged in the second cycle (M=3.35, SD=0.182) compared to the first cycle intervention (M=2.882, SD=0.22), t (39) =9.838, p<0.01 indicating the re-designed cycle helped them to engage more on electrochemistry. The qualitative result from the open ended response and the focus group discussion indicated that students were able to understand the concept of electrochemistry conceptually as they were correctly wrote and tell the concept of electrochemistry specifically electrical conductivity, oxidation-reduction reaction, and galvanic cell. They were able to relate what they are learning in the class with the day to day activities. In addition, the students’ were working passionately during the intervention that incorporates team-pair-solo strategy for dealing electrochemistry contents both in the first and second cycle of the intervention. At the second cycle, there was conceptual change texts incorporated at each stage of the team-pair-solo approach integrating it with technology. The re-designed context of the second cycle resulted both conceptual development and engagement on students’ learning moreover than the first cycle. The researcher concluded that Team-Pair-Solo co-operative learning strategy will develop students’ conceptual understanding and engagement if it is integrated with technology and to some extent conceptual change texts (CCTs). Therefore, the researcher recommended that electrochemical topics such as electrical conductivity, redox reactions, and galvanic cell should be taught and learnt using the integration of technology in Team-Pair-Solo approach of cooperative learning with CCTs.