BaTiO3 sputtering targets of 3 inch diameter were prepared by sintering the CIP (Cold Isotatic Pressing) compacts at 136$0^{circ}C$ for 3hrs. The apparent density and grain size were 97% and 30${mu}{ extrm}{m}$, respectively. After BaTiO3 films were deposited on Si and Pt/Ti/SiO2/Si substrates using these targets, films were annealed at various conditions and the crystallization behavior, reaction with the substrate and the electrical properties were investigated. The films on both substrates required 5~20hrs furnace annealing for crystallization at the temperatures from $600^{circ}C$ to 80$0^{circ}C$. For the films on Si substrate, interaction between the film and the substrate was suppressed upt o $700^{circ}C$ for 10 hrs and the relative dielectric constant was 30. As the annelaing temperature and time were increased, the relative dielectric constants of the films decreased due to the formation of silicate phases through the reaction with the substrate. For the BaTiO3 films on Pt/Ti/SiO2/Si substrate, the reaction with the substrate was further reduced when the annealing condition was identical to that for Si substrate, but the reaction between the layers in Pt electrode took place above $700^{circ}C$. When the films were annealed at $600^{circ}C$ where the stability of Pt electrode was sustained, relative dielectric constant was increased to 110 since the reaction with substrate was effectively reduced even for a longer annealing time and the crystallization was enhanced.