The importance of antimicrobial activity asserts, when chitosanis applied in food, textile industries, for medicine purposes, etc.The antimicrobial activity of chitosan is mainly determined by itschemical composition, i.e. MW and DD. However, due to various experimental conditions, the physical state of chitosan and differ-ences in microorganisms used for investigation, quite contradictorydata of the influence of the molecular weight of chitosan on itsantimicrobial properties are presented in literature