XML enables to migrate data from relational databases and other sources into future applications. It integrates structured and unstructured data to present new application and knowledge management opportunities. By another way, data warehousing is an essential element of decision support, which has increasingly become a focus of the database industry. Meta-data contains data dictionary and repository; it describes warehousing process, data storage and information delivery. This paper defines how XML impacts and changes the concept of the data warehouse. It describes an XML based tool for a structured, reusable and more efficient data warehouse (DW). Otherwise, it shows the ability to specify the warehousing tools with rules defined in the meta-data dictionary.