The effects of marinating on the volatile flavor compounds of Guizhou Sansui characteristic marinated duck was investigated by solid phase microextraction and gas chromatography-mass spectrometry(SPME-GC-MS)， combined with relative odor activity value (ROAV)， cluster analysis (CA) and principal component analysis (PCA) were used to analyze the samples marinated for 0 min， 60 min and 120 min in order to determine the key volatile flavor substances of marinated duck in the process of marinating. The results showed that 67， 94 and 100 volatile flavor compounds， including hydrocarbons， aldehydes， alcohols， esters， ethers and sulfur-containing heterocycles were detected at 0 min， 60 min and 120 min， the richness of flavor increased significantly during the marinating process(P<0.05). Relative odor activity value (ROAV) and cluster analysis (CA) found that there are 28 key flavor substances in the marinating process (ROAV>1). Principal component analysis(PCA) indicated that linalool， hexanal， nonanal， octanal， n-heptanaldehyde， D-limonene， α-pinene， γ-butyrolactone and 1-octene-3-alcohol are the key flavor compounds in different marination stages. Benzaldehyde and phenylacetaldehyde were the characteristic aroma compounds of the samples marinated for 0 min. Trans-2-octenaldehyde were the characteristic aroma compounds of the samples marinated for 60 min. Dodecaldehyde， decanal， 3-hydroxy-2-butanone， terpinene， α-caryophyllene， laurene， α-terpineol， 6-methyl-5-heptene-2-one， terpene oleene， trans basilene were the characteristic aroma compounds of the samples marinated for 120 min. With the extension of marinating time， the types of key flavor compounds of Sansui characteristic marinated duck are more abundant， and the main flavor compounds such as hydrocarbons， ketones and alcohols are added to improve the overall flavor of the Sansui characteristic marinated duck.