LaNiO₃ (LNO) is one of an excellent candidate for oxide electrodes especially for perovskite ferroelectric films since it is perovskite type crystal structure, and therefore it is suitable for lattice matching with conventional perovskite ferroelectrics, Pb(Zr,Ti)O₃ (PZT), BaTiO₃ (BTO), etc. We have been investigating an effect of thermal expansion of the LNO film as PZT/LNO/Si and BTO/LNO/Si structures, where ferroelectric and piezoelectric properties can be improved by a compressive thermals stress implied from the LNO layer to the ferroelectric films. The ferroelectric films also shows high [001] orientation owing to [100] orientation of the LNO film. In the present study, microstructures and crystal structures of the LNO films fabricated on Si substrates by CSD method is investigated by X-ray Diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) in order to understand self-orientation along [100] perpendicular to the film plane. The results obviously indicate that the 1 layer deposited LNO film has almost no orientation, whereas it shows tendency of orientation of [100] perpendicular to the film plane when the layer number increased (upto 4 layers). TEM analysis also shows in-plane tensile stress applied to the LNO film is effectively decreased by porous LNO structure, which leads in-plane compressive stress to the ferroelectric films prepared on the LNO films.