In order to explore the differences of volatile components at different time points of fish sauce fermentation and the influence of fatty acids on the formation of flavor components, GC-MS techniques were applied to identify volatile flavor components and fatty acids in fish sauces during fermentation process. As a result of GC-MS analysis, 56 volatiles components that can be divided into 7 types were identified in fish sauce samples during different fermented time and further quantified based on internal standard analysis. And 12 kinds of key flavor compounds were selected as main aroma compounds, such as 3-Methylthiopropional. Therefore, the main characteristics flavors of fish sauces can be described as mushroom, potatoes, malt, vanilla, fruity and fishy flavors. The main distribution of fatty acids in fish sauce ranged for C15-C26, and the content of unsaturated fatty acid was high up to 67.23%. Moreover, the contents of linoleic acid and linolenic acid related to flavor changed significantly which were correlated with the changes of volatile compounds during fermentation. Accordingly, fatty acids were important precursor substances for characteristic flavor during fish sauces fermentation.