The effect of catalysts which was catalyzed by acid(HNO3) and base (NH4OH) or not on the surface microst-ructures and consequent dielectric characteristics of the PbTiO3 thin films prepared by sol-gel method were investigated. The result indicated that bse catalyst promoted the phase transformation of perovskite phase while acid catalyst was found to produce most uniform surface microstructure and improved dielectric properties However degradation of properties due to secondary phase formation and non-uniform microstructure at high annealing temperature (>75$0^{circ}C$) by rapid diffusion of lead was unavoidable in any case as long as Si(100)＼SiO2＼Pt substrate used,