In　this　paper,　CeO2　buffer　layer　and　YBCO　superconducting　layer　were　deposited　on　the　yttrium　stabilized　zirconia　(YSZ)　single　crystal　by　metal　organic　deposition　(MOD)　method.　The　values　of　Tc　and　Jc　of　the　YBCO　film　were　90.5　K　and　1.3　MA/cm2,　respectively,　it＇s　indicated　that　high　performance　YBCO　film　was　obtained.　But　BaCeO3　phase　was　found　in　YBCO/CeO2/YSZ　film.　Then,　the　formation　condition　of　BaCeO3　and　its　influence　on　the　superconducting　performance　of　YBCO　were　investigated.　The　results　revealed　that　BaCeO3　is　formed　after　the　synthesis　of　YBCO　phase,　and　BaCeO3　is　the　product　of　the　reaction　between　CeO2　and　YBCO,　and　BaCeO3　phase　is　inevitable　during　the　process　of　YBCO　films　by　MOD　method.