The purpose of this study was to investigate preservice science teachers' collaborative knowledge building through socioscientific argumentation on healthy eating in a multiple representation-rich computer supported collaborative learning (CSCL) environment. This study was conducted with a group of preservice science teachers (n = 18) enrolled in a technology in science education course at a large, high research activity university in the Southeastern United States. Data sources were the representations created by the participants in a CSCL platform across three representational modalities, audio recordings of classroom activities and posters created by the groups. To investigate learning in the collective level social network measures of density and centrality were utilized. Furthermore, content analysis and text mining were used to analyze students' representations. Reflected in the participants' wikis, individual learning was assessed using argumentation analysis rubrics and content analysis of representations and posters. Results indicated that the knowledge base created jointly with different representations by the participants was improved, the written argument contents both shared more commonalities in terms of content and shared more common words as a reflection of the participants' collective effort. In an individual level, analysis of the learners' written arguments indicated that some participants increased their argumentation qualities in their final arguments, all participants incorporated more specific scientific knowledge and aspects from other participants' arguments. It was concluded that collaborative knowledge building with multiple representations increase learning both in the individual and collective levels.