—In the Structuring Nanotechnology Knowledge project, a material-independent platform for supporting development of innovative nano-materials is developed. The platform is called “Structured Knowledge Platform for Nano-materials and Products”. It consists of various kinds of resources. However, domains and grain sizes of the resources are different from each other. Therefore, we need a consistent framework to interoperate them efficiently. In this background, we aim to develop a contents management system based on a light-weight ontology which provides a common vocabulary to represent semantic contents of the resources. This article outlines the system with its functionalities.