$LaF_{3}$ thin films have been fabricated on Si (100) substrates under the highest possible vacuum condition by pulsed laser deposition (PLD) method. The temperature of the sbustrate varied from $20^{circ}C$ to $800^{circ}C$. The films deposited at the higher temperature indicated the sharper peaks in the X-ray diffraction measurement. A highly oriented film was successfully obtained at a substrate temperature of $800^{circ}C$. The surface observation by the AFM revealed that the many hexagonal structures constructed the film. The XPS analysis revealed that the lacking of F in the film deposited at $600^{circ}C$ were much more than that in film at $^20{circ}C$. Adding the adequate amount of $CF_{4}$ gas in the growth chamber can compensate this lacking of F.