Cassava starch (CS) has poor water resistance and it is limited to use in applications such as food packaging and medical materials. Lactic acid (CL) modified cellulose was used to improve the properties of CS. In particular, incorporating CL in CS significantly improved the water resistance and mechanical properties. The ester linkage of this sample was confirmed using ATR-FTIR. After the addition of CL, the moisture content and absorption ratio decreased dramatically. The good interfacial adhesion between CS and CL was examined by SEM. The specimen in the presence of CL with 100/0.5 CS/CL has the maximum swelling ratio of 450%. The highest strength was found at 11 MPa when using 100/7.5 CS/CL. The moisture content and absorption decreased as a function of the CL. Finally, the modified CS/CL film could prolong banana shelf life because of the decrease in the respiratory rate of the bananas. An improved CS film can improve the shelf life of bananas by reducing the exhalation ratio of the bananas. The banana CS/CL coating has a good preservative effect on bananas up for 7 days with minimal black/yellow spotting. Also, the biodegradation of CS film occurred easily in natural soil because of its good water absorption. The biodegradation of the CS/CL blend occurred in a range 65–100%. • The good interfacial adhesion between CS and CL was examined by SEM. • The highest strength was found at 11 MPa. • The banana CS/CL coating has a good preservative effect on bananas up to 7 days. • The biodegradation of the CS/CL blend was occurred in ranging with 65–100%.