A pn junction is fabricated by using the pulsed laser deposition (PLD) technique for a ptype YBa2Cu3O7-δ (YBCO) film on the ntype SrNb001Ti099O3(SNTO) single crystal substrate. The measured results reveal that the YBCO thin film is highly corientated structure and shows very good superconducting properties. The YBCO/SNTO pn junction has good rectification property and stability under variation of temperature and magneticfield.