The number of users is interested in generating new contents by utilizing and editing existing videos. In order to utilize the existing videos, a video retrieval system is necessary to retrieve an appropriate source of videos. However, since the existing video retrieval system is based on keyword matching, there is a limitation to find videos they want. In this paper, we propose a query expansion method that can express users' search intention more accurately in order to solve these problems. The proposed method uses the domain ontology and word embedding results to add semantically related words. This allows the user to obtain satisfactory search results. We evaluate the proposed query expanding approach using the implemented retrieval system.