In this study, by combing three research fields of regulative learning, learning analytics (LA) and students' agency in computer-supported collaborative learning (CSCL), the authors tried to illuminate how students regulated their learning though group composition, peer assessment, and LA strategies to foster agency and knowledge (co-)construction activities in CSCL environments. To fulfill this aim, 60 students from Fasa University, Iran were assigned to experimental and control groups based on their self-regulated learning (SRL) skills (high, medium, low, and very low SRL skills). Data analysis confirmed the positive relationship between group composition, peer assessment, LA, regulative learning, agency, and knowledge (co-)construction. The results revealed that through applying group composition, peer assessment, and LA, socially-shared regulated learning, co-regulated learning, and consequently SRL skills were improved, which finally fosters agency and knowledge (co-)construction activities in CSCL environments.