Industrial Symbiosis describes cooperations between industrial actors to create economic value from waste and to reduce its environmental impact. Although the advantages of such cooperations have been demonstrated in research and practice through many case studies it is not an established concept yet. The concept of Industrial Symbiosis is supported by the development of information and communication technologies, which increasingly take the form of online platforms, and help to mitigate information and social barriers. However, most tools are not comprehensively documented, not accessible for new participants, not operational or not used. Motivated by the potentials of platforms to provide support for the emergence of Industrial Symbiosis and the number of unsuccessful platforms, we analyze the relationships, roles and phases in Industrial Symbiosis against the background of the current platform ecosystems theory. Based on these findings, we give a design guidance for Industrial Symbiosis Platforms.