Abstract: Disclosed are thin film deposition system and method. The thin film deposition system includes a reaction chamber; at least one susceptor installed in the reaction chamber for mounting a substrate thereon; a first gas sprayer rotatably located above the susceptor; and at least one second gas sprayer installed above the first gas sprayer for spraying purge gas. The thin film deposition system increases the absorption rate of source gas onto the surface of the substrate, efficiently shortens the supply cycles of the gases to improve the productivity thereof, and improves the cleaning effect of the purge gas so that a thin film is stably deposited on the substrate.