Highly (001)-, (100)-, (101)-, and (110)-oriented (Pb0.90La0.10)Ti0.975O3 (PLT) thin films were deposited on the LaNiO3(001)/Pt(111)/Ti/SiO2/Si(100), LaNiO3/SiO2/Si(100), PbTiO3/Pt(111)/Ti/SiO2/Si(100), and LaNiO3(110)/Pt(111)/Ti/SiO2/Si(100) substrates by rf magnetron sputtering. The orientation dependence of ferroelectric properties of the PLT films was investigated. The result shows that the (001)-oriented PLT thin films exhibit enhanced ferroelectric properties (2Pr=61.1 μC/cm2 and 2Ec=179 kV/cm). The residual stress of the PLT thin films with different orientations was measured by x-ray diffraction (sin2 Ψ method) for illuminating the related physical mechanisms. The result shows that the enhanced ferroelectric properties of (001)-oriented PLT thin films should be attributed to low residual stress.