The aim of this work was to build up starch-based bioactive films from corn starch, glycerol, citricrnacid, and cinnamon bark oleoresin and characterize its physical and mechanical properties, andrncheck its antimicrobial effect. The processing variables were optimized to study their effect on thernfunctional properties of bio- films. Glycerol concentration (20, 30, & 40%v/w), citric acidrnconcentration (0, 5, & 10%w/w), and drying temperature (30, 60, & 90oc) as independent variablesrnwhich produced 20 different combinations, were studied using response surface methodology torninvestigate the effect of these variables on the product responses. The glycerol concentration was thernmost influential parameter for the physical and mechanical properties of the prepared packagingrnfilms followed by citric acid concentration and drying temperature. The numerical optimization gavernin glycerol concentration (27.86ml glycerol/100g corn starch), citric acid concentration (0.29g citricrnacid/100g corn starch), and drying temperature (62.84oc) as optimum variables to produce betterrnfilms. Using the optimized variables the films were re-prepared and the functional groups werernidentified using FTIR. The bio-films were again prepared using the optimized variables with thernaddition of Cinnamon bark oleoresin (0%, 10%, and 12% v/w of dry starch) in order to analyze itsrnantimicrobial activities against the target microorganisms Escherichia coli, Staphylococcus aureusrnand Pseudomonas aeruginosa. The cinnamon bark oleoresin showed clear inhibition zone againstrnthe tested microorganisms whereas the bio-films containing the oleoresin showed surface inhibition.rnKeywords: Antimicrobial activities, Starch based bioactive films, Target microorganisms