This independent study was a quasi-experimental research ; the purpose of the research was to study the development of Mattayomsuksa 1 students’ English speaking skill using cooperative learning strategy based on a team-pair-solo technique : at Banhaedsuksa School, Banhaed District, Khon Kaen Province. The sample selected by purprosive sampling group were 36 Mattayomsuksa 1 students. The instruments used in this independent study consisted of 4 three-hour lesson plans, and an English speaking skill test. The content validity ranged between 0.80-1.00 ; the reliability of total issue was = 0.77 ; the index of item objective congruence, (IOC). The statistic used for data analysis included frequency, percentage, mean, standard deviation and the t-test (Dependent Sample). The findings were as follows: 1. The students’ overall English speaking ability was at a 0.05 level significantly higher after learning with the use of the cooperative learning strategy based on the team-pair-solo technique. 2. The comparison of the students’ overall English speaking skill test was at a 0.05 level significantly higher after learning with the strategy based on the team-pair-solo technique. The students’ development of English speaking skill was clearly higher. 3. The comparison on the students’ overall English speaking ability test before and after learning with the use of the cooperative learning strategy based on the team-pair-solo technique, was at statistically significant different of .05 level level. The students’ development of English speaking skill was at the “higher” level. 4. The students’ overall satisfaction with the development of English speaking skill with the use of the cooperative learning strategy based on the team- pair-solo technique, was at the “highest” level.