The open access repository means the knowledge information repository for the producer and the user to share in order for all users of the world to freely access the information free of charge with no legal, economic and technological barrier. This study analyzes and compares the functions offered by each repository by classifying the repository into the organizational repository (dCollection, DSpace@MIT) and the thematic repository (arXiv, PubMed Central) and evaluates the user-centered usability based on the analyzed data. This study at the current times, so called as the Web 2.0 era in which the free access and sharing of the information is important, can be said to have the meaning that the result from the usability evaluation on the open access repository will be used as the fundamental data for developing the future repository.