The goal of Millenium Development Goals 2015 to reduce the poverty rate is predicted will not be achieved by 2015 which caused by the failure of market mechanism, government policy, and civil organizations initiative. The concept of Social Innovation as a multi-stakeholder approach is an alternative approach to solve a social problem with the collaboration of tripartite sectors. However, the concept of social innovation that runs with cross partnership requires an integrated knowledge management system so that the social innovation resources can be accumulated. This research designed a social innovation knowledge management system that will collaborate tripartite sectors to accumulate social innovation resources and solve social problems. The methodology used in this research is the SECI Model Analysis. This includes knowledge characteristic analysis and formulation for creating and transferring tacit-explicit knowledge. The output of this research is the model of Kreanovator Indonesia's knowledge management system that will be interpreted into a form of website's menu design (interfaces) of online platforms for open social innovation project, the community of practice for social innovation, open volunteerism, crowdfunding, and changemakers hub for the tripartite sectors.