Abstract:The dynamic changes in the flavor components of oat Laozao during the fermentation process were studied comprehensively. Sampling was performed at different time points during the whole fermentation process for measurement of the content of free amino acids，volatile components，total acids，and ammonia nitrogen. The results showed that the total free amino acids and ammonia nitrogen in oat Laozao first increased and then decreased，and the total acids showed an overall upward trend during the fermentation process.The volatile components of oat Laozao included alcohols，esters，acids，aldehydes，ketones，heterocyclic compounds，and hydrocarbons，in which esters，acids，and alcohols had high content（reaching 95%），being the main volatile components of oat Laozao. The esters in oat Laozao during the fermentation process first increased and then decreased，while alcohols presented an increasing-decreasing-increasing trend. The content of acids and heterocyclic compounds kept rising，and that of aldehydes，ketones，and hydrocarbons first declined and then elevated. The principal component analysis（PCA）results demonstrated that the cumulative contribution rate of the first two components（PC1 and PC2）was 97.761%. The content of esters，alcohols，heterocyclic compounds，and acids was positively correlated with PC2，while that of hydrocarbons，aldehydes，and ketones was positively correlated with PC1. PCA clearly distinguished the samples at different time points of fermentation.