Objective: To analyze the volatile constituents of Cydonia oblonga seeds and provide experimental basis for reasonable development and utilization of C. oblonga seeds. Method: Steam distillation method was used to extract the volatile oil of C. oblonga seeds

and its volatile constituents were analyzed by gas chromatography-mass spectrometry (GC-MS) combined with retention indices. Their relative percentage contents were determined with peak area normalization method. Result: The 38 chemical constituents were isolated from the C.oblonga seeds

and 24 compounds of them were identified

accounting for 98.56% of the total volatile oil. The main constituents included benzaldehyde (46.37%)

(Z)-octadec-9-enoic acid (30.54%)

n-hexadecanoate (6.13%)

carotol (2.37%)

3-methyl-butyraldehyde (1.81%)

furfural (1.37%)

2-methyl-butyraldehyde(1.22%)

and 2-butyl benzene acetate (1.17%). Conclusion: The aldehydes (51.92%)were the main volatile constituents in C. oblonga seeds

followed by acids (31.25%).