Abstract: In order to clarify the characteristic flavor components of Freshwater Crawfish and further explore the effect of ultra-high pressure(UHP)processing on the flavor of Freshwater Crawfish,Characteristic flavor components of Freshwater Crawfish tailmeat were confirmed before and after the certain ultra-high pressure processing and influence of UHP processing on Freshwater Crawfish tailmeat flavor was also studied by response surface methodology(RSM). Key flavor compounds in volatile components of Freshwater Crawfish tailmeat which determined by solid phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)were confirmed by relative odor activity value(ROAV)with threshold. The results showed that 54 and 48 kinds of volatile components were determined in Freshwater Crawfish tailmeat before and after the specific UHP treatment and 37 kinds of volatile components were common. The key flavor compounds of Freshwater Crawfish tailmeat after UHP treatment were 9 compounds of hexanal,heptanal,octanal,nonanal,decanal,dodecanal,2-decanone,2-undecanone and 2-pentyl-furan which 1(2-undecanone)more than Freshwater Crawfish tailmeat without UHP treatment. The influence of holding time and pressure temperature on flavor of Freshwater Crawfish tailmeat was significant(p<0.05),it should be done that reduce holding time and pressure temperature based on good quality for getting better flavor of Freshwater Crawfish products.