The present application relates to a method for preparing a barrier film. The present application can provide a method for preparing a barrier film having excellent barrier characteristics and optical performances. The barrier film produced by the method of the present application can be effectively used not only for packaging materials of as foods or medicines, and the like, but also for various applications, such as members for FPDs (flat panel displays) such as LCDs (Liquid Crystal Displays) or solar cells, substrates for electronic papers or OLEDs (Organic Light Emitting Diodes), or sealing films.