LaNiO3 (LNO) has been used as bottom electrode layer for ferroelectric and antiferroelectric thin films due to its good conduction, preferred (100) orientation, same crystalline structure as many perovskite ferroelectrics and antiferroelectrics, good adhesion and compatibility with the Pt/Ti/SiO2/Si template. In this study we have investigated the ideal optimal post - annealing conditions for LaNiO3 thin films deposited at 450°C using a magnetron sputtering method. Heat treatment from 500 to 1200°C was performed. Scanning electron microscopy (SEM), x-ray diffraction (XRD) and electrical measurements were carried out to characterize the morphology, structure, and macroscopic properties. Results indicated that the LNO film had the best quality when annealed at about 800°C. Above this temperature, the morphology, structure and associated properties would deteriorate.