Metadata management is an important component in data warehouse. In the column-oriented system, data is stored by columns while metadata is still accessed in the way of rows, so it is a problem to convert columns into rows efficiently. Studies have shown that the strategy of converting column into row is an important issue for the performance of column stores. However, till now how to manage metadata in column-oriented data warehouse hasn't been addressed in a standardized or an efficient way. This paper propose a novel method for metadata design and column to row (C2R) conversion in the column-oriented data warehouse management system (DWMS). Besides saving space for the reconstruction of metadata, C2R can improve the hit rate of metadata queries in the share pool and reduce the responding time. The effectiveness of the column-row conversion algorithm C2R and the metadata management strategy have both been verified through experiments.