This study analyzes information systems conversion of cooperatives from the perspective of sociomaterial practice. We intend to explain the dynamics of information system (IS) beyond one-sided understanding of success and failure, and acceptance and resistance of users from technological deterministic perspective. It considers of technology as exogenous, homogeneous, predictable, and stable and performing as intended in general. However, information communication technology (ICT) which is essential technology in contemporary society and organizations shows the characteristics of dynamics, multiplicity, connectivity, and dispersion. These characteristics of ICT indicates a relational ontology that social and material is constitutively entangled and could explain as sociomaterial practice perspective. A cooperative is an enterprise with democratic managerial principles based on its member’s co-ownership, and they have the autonomy to participate in overall decision-making. These characteristics show the dynamics of IS conversion more clearly than that of investor-owned firms. The IS conversion of Happy Bridge shows that the initially introduced IS is reconstituted into ‘exclusion of some functions, arbitrary use of some functions, and modification of some functions’ through member’s ICT use practices. This demonstrates that ICT could be dynamically reconstituted by being constitutively entangled with user’s practices rather than being fixed and performed as intended. The results of our study suggest that sociomaterial practice perspective is valuable in explaining the phenomena that technology creates with people in organizational studies. The strength and limitation of this study is that it analyzed worker cooperatives with a different governance from investor-owned firms. However, the study is meaningful in that it is introduction of the perspective of sociomaterial practice in Korea that it is conducted rarely in IS studies. It will be a challenge in the future to expand the scope of IS studies by expanding the research to various types of organizations such as non-profit organizations and investor-owned firms in Korea, and verifying the theoretical significance of sociomaterial practice.