Zinc oxide/sodium cellulose composite with different ZnO loadings was prepared for the first time. The crystal structures of cellulose, sodium cellulose, and ZnO/sodium cellulose composite were characterized by FT-IR, XRD, XPS, SEM, and EDX. ZnO/sodium cellulose showed a similar XRD pattern to that of cellulose II. The XPS spectrum emphasized the presence of Zn$^{2+}$ and Na$^{+\, }$ ions in the prepared composite. Additionally, the SEM analysis showed the growth of ZnO crystals on the sodium cellulose surface. UV-Vis spectrometry of the ZnO/sodium cellulose spectrum showed a distinguished absorption band at 360 nm that was attributed to the presence of ZnO particles on the cellulosic fibers. As a result, the composite fibers swelled, and their diameter increased from 15 \textmu m to 30 \textmu m. Furthermore, ZnO/sodium cellulose exhibited lower air and water vapor permeability than cellulose and sodium cellulose and can be perfectly utilized as food packing film to increase the shelf life of preserved foods.