Abstract: A method of liquid-liquid extraction and gas chromatography-mass spectrometry(GC/MS) analysis was developed for the determination of tetramine in blood. The extraction rate of nine kinds of organic solvents including benzene, chloroform, acetic ether, acetone, dichloromethane, aether, cyclohexane, hexane for tetramine were researched. The results showed that the extraction yield of acetic ether for tetramine is above 90%, and it is an ideal extraction solvent; tetramine work curve was y=12 543.3*x+516.2, r= 0.998 3, the detection limits were 2μg/L; GC/MS spectrum of tetramine was also analyzed without standard library spectrums, and main GC/MS spectra of tetramine were identified. Blood from victim was determined by GC/MS-SIM, detection limit was increased and interference was decreased. The extraction and analysis method of tetramine established was suitable for the judicial identification.