Abstarct: Due to environmental pollution, tend to use biodegradable packaging is on the rise. On the other hand, although conventional heating methods, due to increase consumer confidence and shelf-life of food products, but at the same time it will also reduce the quantitative and qualitative factors. Therefore, in addition to biodegradable packaging design, create antimicrobial packaging and safety using natural antimicrobial agents is very important. Chitosan and essential oils are known as antimicrobial agents that could be used in antimicrobial packaging. In this study, the covalent bond between benzoic acid (BA) and chitosan (CS) was created and then CS-BA nanogel using self-assembled method was obtained. Rosmary essential oils (REOs) were encapsulated in CS-BA nanogel in order to enhance antimicrobial activity and stability of the oils. Then REOs in the free and encapsulated forms were used in corn starch-baxsed edible films and its physical, mechanical and antimicrobial properties were studied. Results of FT-IR showed that covalent bond between the CS and BA have been successfully completed. SEM image showed the average particle size below 100 nm. Films containing nanogel had a water vapor permeability higher compared to films containing REOs. Moisture absorption of films decreased with increasing REOs and nanogel. In the case of films containing nanogel to a concentration of 0.2% transparency increased. Film containing 0.2% nanogel had the highest tensile strength at break point. The microbial test results showed that the REOs and nanogel each alone had a good inhibitory effect against Staphylococcus aureus and by encapsulation inhibitory effect of REOs was increased. By combining REOs and nanogel, both immediately (REOs) and gradual (Nanogel) antimicrobial effects against S. aureus were obtained. According to the results of this study, starch-baxsed edible films containing encapsulated REOs in CS-BA nanogel can be used to enhance the shelf life of food products.