The current work focuses on the synthesis of the biodegradable film made from Sodium alginate (S.A), and then the addition of magnesium oxide nanoparticles (MgO-NPs) was synthesized by sol-gel technique. Glycerol which is a plasticizer is used to enhance the tensile strength (TS) and film expansion due to a decrease in intermolecular forces in the polymer chain. With the addition of olive oil (OE), the functional properties of control films were improved, which results in a lowering of water solubility, and moisture content but the tensile strength slightly decreased. The opacity, moisture absorption, and solubility of the film, thickness, tensile strength (TS), elongation (EB), ultraviolet-vis spectroscopy, scanning electron microscope (SEM), transmission electron microscopy (TEM) were used to characterize sodium alginate biofilm with the addition of MgO-NPs (SA1) and without the addition of MgO-NPs (SA2). But considering all other factors, the film (SA1) revealed a slower rate of degradation than the film (SA2). The film's TS and opacity are enhanced by MgO-NPs addition, while moisture content (WVP), solubility, and elongation at break are decreased.