T he volat ile compounds of aqueous muscle ext ract of P. or ientali s by GC..MSD w ere ex amined. The experimental data indicated that some compounds such as alkyl py razine, thiazole, pyridine, indole, dithiazine, t rithiolane and so on had great inf luence upon shrimp f lavor. T he model system was set up by the addit ion of proper compounds, such as Gly, Ala, Arg and IMP. The change of major compounds in the dif ferent systems w as discovered. A comparison of volat ile compounds in w ild praw n w ith those in cultured praw n w as also studied. The result s indicated that the major f lavor precusors of P . or ientali s included free amio acids of Gly ,Ary, Ala and Cys, carbonhydrates and water soluble proteins.