We propose a tool to manage several sorts of relationships among RDF and RDFS. Our tool consists of three main functions: graphical editing of RDF contents, graphical editing of RDFS contents, and meta-model management facility. Metamodel management facility supports maintenance of relationship between RDF and RDFS contents. The above facilities are implemented based on plug-in system. We provide basic plug-in modules for consistency checking of RDFS classes and properties. The prototyping tool, called MR^3 (Meta-Model Management based on RDFs Revision Reflection), is implemented by Java language. Through the experiment of using MR^3, we show how MR^3 contributes the Semantic Web paradigm from the standpoint of RDFs contents management.