Abstract: 【Objective】 To study the characteristics of volatile organic compounds (VOCs) in leaves of three walnut varieties, compare the differences of VOCs among leaves of each walnut, and construct the scent fingerprint of VOCs of three walnut varieties. 【Methods】 Gas chromatography-ion mobility spectrometry GC-IMS was used to analyze the odor fingerprints of volatile substances in the leaves of Hickory walnut, Wen185 and American red walnut, and variance analysis and principal component analysis were used to analyze the differences in the fingerprints of volatile substance odor in their leaves. 【Results】 The volatile substances were contained in the leaves of different walnut varieties including alcohols, esters, aldehydes, terpenes and a small amount of ketones and furans. The contents of ethyl acetate, β-pinene dimer and acetone in walnut were significantly different from those of Wen185. The contents of 2-vinylaldehyde, cineole and 2, 5-dimethylfuran in walnut were higher than those of Wen185 and American red walnut. 【Conclusion】 There are significant differences in the fingerprint profiles of Hickory walnut, Wen185 and American red walnut, and the content of alcohol was higher in Hickory walnut, and the content of terpenes was higher in American red walnut. The content of Wen185 in esters was higher than that of Hickory walnut and American red walnut.