Using 3-Pyridine carboxylic acid as materials, 3-pyridine carbonyl chloride was obtained via acylation reaction. The acylated α - amino acid reacted with methanol to generate the corresponding amino acid l ester hydrochloride. At room temperature, using triethylamine as deacid reagent, the target products that N- ( 3- formyl pyridine ) -proline methyl ester was obtained at the acylation reaction of 3-pyridine carbonyl chloride with amino acid ester. The structures of all the compounds were confirmed by 1H NMR、13C NMR、IR、HRMS spectra. Then the applications of the ester in cigarette flavoring were studied as well. More than 40 kinds of pyrolysis products were authenticated. Most of the pyrolysis products were aroma components. The smoke panel test showed that the new compound could improve the cigarette taste and flavor, reduce smoking irritation of cigarette.