Hierarchical categorization is a powerful and convenient method so that it is commonly used in various areas, such as ontologies. Although each hierarchy is useful, there are problems to manage multiple hierarchies. In this paper, we propose an alignment method between concept hierarchies by using the similarity of the categorization and the contents of the instance. By using this method, instances that exist in one hierarchy system but does not in the other can be located in a suitable position in the other. The experimental results show improved performance compared with the previous approaches. Hierarchical categorization is a powerful and convenient method so that it is commonly used in various areas. Although each hierarchy is useful, there are problems to manage multiple hierarchies. Similarity-based integration (SBI) [2] is an effective method for solving this problem. By using this method, instances that exist in one hierarchy system but does not in the other can be located in...