The purpose for integration system is to provide a unified, global view to the user over various heterogeneous sources. To answer user queries, a data integration system employs a set of semantic mapping between and mediated schema(global schema) and schemas of data sources (local schema). Such data integration raises main challenging issue: (1) Scheme creations and (2) Schema mappings. In order to address these two fundamental metadata ingredients that are the core of such integration system, we propose a novel approach to integration systems which uses XML schemas based mappings. In this approach, XML Schema allows entertaining manager to manage data models intuitively. XML Schema-based mapping represents the relations between the local schema and global schema. We present the design and implementation of a prototype system based on XML schema.