Studying online has currently evolved into a global 'new normal' trend in education. However, students' intention to adopt online interactive behaviors is still relatively low, and few studies have attempted to obtain an in-depth understanding of students' online interactive behaviors. This study aims to explain and predict students' intention to adopt online interactions by synthesizing the theory of planned behavior (TPB) with cognitive and motivational factors. The proposed model was validated by surveying 368 junior high school students in China who had experienced formal online education for one semester. The results showed that perceived behavioral control was the strongest predictor of students' adoption of online interactions, followed by subjective norms and attitudes, while cognitive and motivational factors were significant antecedents of the three core constructs of TPB. These findings of the study provide valuable insights to understand secondary school students' learning behaviors in an online context and improve their adoption of online interactive behaviors.