The purpose of this study is to investigate the effect of PBL based blended instruction utilizing AI platforms on L2 learning. For this purpose, PBL based online and offline instruction utilizing various AI tools was implemented for one semester with 33 middle school students. Data were collected via English achievement tests and surveys on students’ affective factors and satisfaction on this instruction and t-test, ANOVA and Post-Hoc test were used to analyze the data. The results of this study were as follows. First, PBL based blended instruction utilizing AI platforms enhanced students’ overall English achievement. Especially students’ speaking and writing skills were improved significantly. Second, this instruction improved students’ affective factors significantly: interest, participation, motivation, and confidence. Third, students showed a high level of satisfaction toward this PBL based blended instruction overall. Findings and pedagogical and research implications are discussed.
