Hexagonal　tantalum　pentoxide　(δ-Ta2O5)　epitaxial　films　were　successfully　prepared　on　Y-stabilized　ZrO2　(YSZ)　(111)　substrates　by　metalorganic　chemical　vapor　deposition.　The　crystal　structure　and　optical　characteristics　of　the　deposited　films　as　a　function　of　the　substrate　temperature　were　investigated.　High　quality　stoichiometric　single-crystalline　δ-Ta2O5　film　was　gained　at　the　optimum　epitaxial　growth　temperature　of　800　°C　and　the　full-width　at　half-maximum　of　the　ω　rocking　curve　of　δ-Ta2O5　(0001)　was　only　0.066°.　The　heteroepitaxial　relationship　between　the　δ-Ta2O5　film　and　YSZ　(111)　substrate　was　identified　as　δ-Ta2O5　(0001)YSZ　(111)　with　δ-Ta2O5　[21¯1¯0YSZ　[101‾]　and　was　illustrated　in　a　schematic　diagram.　This　proposed　film　makes　adequate　preparations　for　developing　a　range　of　ultra　wide　band　gap　semiconductor　devices.　©　2020