The preparation of LiNbO 3 films on Si substrates was improved by adding CH 3CH 2OH solution containing a little water to the sol of LiNb(OC 2H 5) 6. The crystallization behavior of LiNbO 3 films on Si (111) substrates was studied and completely c axis oriented LiNbO 3 films were obtained. Such factors as the hydrogen termination of silicon surface, the RTP annealing process used, the unidirectional heat flow and the preheating temperature were taken into consideration while the crystallization of c axis oriented films was analysed. Surface morphologies of the films annealed in RTP and conventional furnaces were observed by means of AFM. The preparation of LiNbO 3 films on Si substrates was improved by adding CH 3 CH 2 OH solution containing a little water to the sol LiNb (OC 2H 5) 6. The crystallization behavior of LiNbO 3 films on Si (111) substrates was studied and completely Such factors as the hydrogen termination of silicon surface, the RTP annealing process used, the unidirectional heat flow and the preheating temperature were taken into consideration while the crystallization of c axis oriented films was analyzed. Surface morphologies of the films annealed in RTP and conventional furnaces were observed by means of AFM.