The purpose of this paper is to investigate the effects of thought-provoking questioning.. strategies on the quality of argumentation and the collaboration load in SNS based collaborative learning and find the suitable strategy for learners`` cognitive structure. 72 participants were randomly assigned into 3 groups (without TPQ prompt, present TPQ prompt before learning task, present TPQ prompt after learning task). The quality of argumentation was analysed by both of quality of individual argumentation and group argumentation. Collaboration load was assessed by self-report questionnaire after collaborative learning. According to the result of research, the strategy which is presenting TPQ prompt to learners before learning task was the most effects on promoting the quality of group argumentation and helped learners to reduce unnecessary collaboration load and promote germane collaboration load.