YBa2Cu3O7−δ (YBCO) thin films, doped or undoped with BaSnO3, are deposited on single crystal SrTiO3 substrates using a pulsed laser deposition system. The optimized temperatures for BSO–YBCO and pure YBCO are different, while BSO–YBCO needs higher growth temperature of 850 °C. And the films being grown at different temperatures exhibit very different surface morphologies. The optimized BSO–YBCO film shows higher critical current density values at different measured temperatures compared to the pure YBCO film, either with or without applied magnetic field. The doped sample obtains self-field Jc of 38.5 MA/cm2 at 40 K, 3.2 MA/cm2 at 77 K, which suggests that BSO doping has effective pinning effects for YBCO superconducting properties improvement.