The present disclosure provides a method and an apparatus for storing data classification structure. Based on an initial classification structure tree, a reorganized classification structure tree that stores data classifications structure differently from that of the initial classification structure is generated. As the reorganized classification structure tree is flexible, when maintaining data and searching data by using the search engine, the present techniques may quickly find the desired data, thereby reducing the heavy burden of the search engine under the conventional techniques to conduct data search and high pressure of conducting data maintenance and data search. Further, the present techniques may not only reduce the burden of the search engine, but also relieve the pressure for maintaining data and searching data.