Since 2007,the green tides have periodically occurred Yellow Sea,drifting from south Jiangsu to Shandong Peninsula.The large-scale blooms of Ulva prolifera have resulted in tremendous economic loss due to the destruction of marine ecosystems and damage to ecological service functions.How to use the large-scale floating biomass of U. prolifera is urgent now.In order to explore the differences of volatile flavor compounds during green tide drifting in Yellow Sea,headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry(GC-MS) were used to extract and analyze the volatile components of U. prolifera from eight sea areas in Yellow Sea.A total of 187 compounds were detected,including aldehydes,alcohols,esters,phenols,ketones, olefins,alkanes and other compounds; 72,64,49,53,34,48,41 and 54 compounds were detected from samples in eight different sea areas,respectively from south to north in Yellow Sea.Through the analysis of the threshold value and compound content of all aroma components in water,it was found that the main aroma components of green tide algae changed in the process of drifting northward,and they showed unique flavor in each region.Generally,flavor quality of U. prolifera from south Yellow Sea was better than north Yellow Sea.This study supplies the possibility of development of food flavor and resource utilization of U. prolifera,which has high research values and broad applications in the future.