In a traditional data warehouse, "subject oriented" means that all the measurements relating to the same real-world event or object are linked together. The measurements are classified and navigated by "subject". But in a multi-use data warehouse, users want to classify and navigate the measurements by mutable cross-classifications flexibly. It is hard to find a universal "subject" to support all usages. In this paper, we propose a classification cube for navigating measurements by cross-classifications, the cell of classification cube is a facet which is aggregated by classification-specified measurements. The model supports to switch classifications, to combine classifications into a cross-classification, and to navigate to any classification-specified facets easily by queries and OLAP operations, further to provide users a flexible and customized view of measurements. At last, some experiments show that the proposed model is effective.