(Bi, La)3Ti4O12 (BLT) thin films were prepared on various sized Pt-coated Si (Pt/Ti/SiO2/Si(100)) substrates by chemical solution deposition method. The crystalline orientation of BLT thin films is drastically changed by the substrate size. c-axis preferentially oriented films were obtained on larger, 30 mm square, substrates. On the other hand, randomly oriented films were obtained on smaller, 10 mm square, substrates. The surface morphology of randomly oriented BLT thin films deposited on a 10 mm square substrate showed rod shape grains which lying along random directions. On the other hand, c-axis oriented BLT thin films which were deposited on 30 mm square substrate showed a layered structure. The remnant polarization and coercive field of BLT thin films deposited on 10, 15, 20 and 30 mm square substrates measured at 360 kV/cm are 14.3, 16.0, 8.24, and 8.79 μC/cm2; 60.1, 81.4, 80.4 and 78.6 kV/cm, respectively.