Abstract: In this study,the optimal preparation processing of crab flavoring essence by Maillard reaction using uniform design methodology combining with sensory evaluation method was explored with crab hydrolysate as raw materials,and the volatile flavor composition before and after the reaction were investigated and compared by SPME- GC- MS.Experimental results suggested that the optimal conditions of Maillard reaction were glucose 6.7%,xylose 2.0%,glycine 0.6%,arginine 2.2%,taurine 0.1%,thiamine 1.4%,temperature 101 ℃,time 33 min,p H7.5,the product prepared under this condition exhibited strong meaty and seafood aroma with uniform reddish brown.Meanwhile,24 and 43 kinds of volatile flavor components were separated and detected in hydrolysate and Maillard reaction product,respectively. The product mainly contains 8.82% ketones,30.87% aldehydes,18.83% furans,20.04% pyridine,6.35% alcohols and some other volatile flavor compounds. Furthermore,the predominant odourants were 2,3- butanedione,3- methylthiopropanal,2- methyl- pyrazine,1- octene- 3- ol and other components with lower threshold value,which exhibited a significant contribution to overall special aroma.