Abstract: The 10-undecenal glycol acetal was synthesized from 10-undecenal and glycol.The synthetic conditions and application of the acetal in cigarette were experimented.The results showed that the optimum conditions for the acetalization were:the molar ratio of undecental to glycol was 1:1.25, p-toluenesulfonic acid was used as a catalyst, hexane as a solvent and heating for 60 min at refluxing temperature.The highest yield of the acetal was 98.74%.The acetal was capable of imparting to cigarette a characteristic flavor of brewing sweetness, reducing smoke irritation and improving smoking quality.