In this paper, we propose an approach to materialize XML data warehouses based on the frequent query patterns discovered from historical queries issued by users. The schemas of integrated XML documents in the warehouse are built using these frequent query patterns represented as Frequent Query Pattern Trees (FreqQPTs). Using hierarchical clustering technique, FreqQPTs are clustered and merged to produce a specified number of integrated XML documents for actual data feeding. Maintenance issue of the data warehouse is also treated in this paper. Categories and Subject Descriptors H.2.7 [Database Management]: Database administration –Data warehouse and repository. General Terms: Management. Keywords Data Warehouse, XML Data, Query Patterns, Data Integration