Ontology ranking is one of the important functions of ontology search engine and plays an important role for ontology reuse. It facilitates effectively user to choose the reusable ontologies from the search results returned by ontology search engine. The current ontology ranking methods can not satisfy user because of various defects. On the basis of analyzing the existing ontology ranking methods, we think both the correlation among the ontologies and the matches between the query and ontologies should fully be considered on ranking ontologies. An ontology ranking method is proposed based on Formal Concept Analysis in this paper. The experimental results show that the proposed method is better than that of hyperlink analysis and content analysis. Ontology search engines will get benefit from our method because if can also help user to choose efficiently suitable ontologies to reuse.