In this study, the barrier properties, crystalline structure and morphology of pullulan–sodium alginate-based films were investigated. Among the tested samples, pure pullulan films exhibited the lowest water vapor permeability and oxygen permeability values (7.05365×651061665g.m/Pa.h.m2 and 0.48x10616 mL.mm/m2day.pa, respectively). Incorporating pullulan into alginate, the absorbance bands of COO61 groups shifted significantly to higher wavenumbers (1,640 and 1,41365cm611, respectively). This could be attributed to the disruption of intermolecular hydrogen bonds present originally between the carboxylic groups caused by added pullulan. The diffractogram of pullulan films indicated that pullulan was a fully amorphous polymer, whereas that of sodium alginate exhibited semi-crystalline features. Furthermore, the morphology of pullulan–alginate-based film was studied by atomic force microscopy. Roughness parameter ( R q and R a) values increased significantly with the incorporation of alginate content into pullulan. Practical Applications Because pure pullulan, alginate and their blend film are highly water soluble, transparent, tasteless, odorless and heat sealable and poses low permeability to oxygen, they could potentially be a secondary packaging material for beverage products such as instant coffees and cocoa.