Sausage is a food that is much favoured by the Indonesian people. Sausage belongs to a group of frozen food products that require cold storage. The weakness of sausages is to become stale when opened and exposed to the free air. It encourages sausage manufacturers to use preservatives in their products. A natural preservative that does not cause negative effects is chitosan from shrimp skin. The purpose of this study was to determine the optimum concentration of chitosan, which can be used as a natural preservative in sausages. The method used was experimental research by developing and utilizing chitosan in various concentrations, namely 1%, 1.5%, 2%, and 2.5% as experimental treatment and 0% chitosan concentration as a control treatment. The five treatments were observed in terms of organoleptic test and bacterial count test. The organoleptic test was performed at room temperature. The results showed that sausage with 1% chitosan edible film can maintain the quality of the sausage. Chitosan with a higher concentration makes the chitosan solution more concentrated, thus it becomes ineffective since it affects the appearance and performance of sausages. The use of 1% chitosan maintains the sausage quality of three days of storage and it indicates the number of bacteria is only 1.7×103 CFU/g with a clear zone area of 5.41±1.10 mm. It concludes that the concentration of 1% chitosan is the optimal concentration that can be used to inhibit the growth of bacteria in sausages compared with other concentration treatments.