Students' social knowledge construction and socio-emotional interactions in computer-supported collaborative learning (CSCL) are shaped by one another and work together to affect the group's learning performance. However, few studies have combined both social knowledge construction and socio-emotional interactions and examined how they contribute to improved learning performance. This study examines the dynamics of students' social knowledge construction and socio-emotional interactions in the context of computer-supported collaborative writing and compares six high- and six low-performing groups. Quantitative content analysis and sequential analysis were used to reveal the characteristics of groups' behaviour frequencies and patterns. The high-performing groups demonstrated more systematic and meaningful social knowledge construction and socio-emotional interaction patterns, while the low-performing groups only engaged in single repeated behaviours. It is worth noting that memes played different roles in the two groups.