Highly (100) oriented PLT (La/Zr/Ti: 14/0/100) seeding layers have been developed on glass substrates by the optimized sol-gel process. The early growth stages of the seeding layers have been studied by continuously decreasing film thickness to tens of atomic layers (∼8 nm thick) from ∼50 nm and Volmer–Weber growth mode has been observed. The seeding layers consist of islandlike clusters inside which the grains were radially assembled. The mechanisms for the oriented growth of the seeding layers were then explained. The seeding layers with different island densities could induce distinct orientation degree and perovskite formation for the subsequently deposited PLZT (9/65/35) films. The PLZT films grown on continuous seeding islands exhibited the highest orientation degree and desirable optical and electro-optic properties.