Most drugs of amphetamines contain chiral centers, which form different optical isomers, or enantiomers. Because different enantiomers have different pharmcological effect and have different machnism of metabolism. Besides, the ratio of the two eanatiomers could reflect the route and method used in the synthesis of the drugs. So the separation and determination of these eanantiomers for seizured samples or for biological samples became very important in the sence of forensic science.The paper used two chiral reagents: N-trifluroacetylprolyl chloride (TPC) and ( R )-( + )-α-methoxy-α-(trifluormethyl)phenylacetic acid (MTPA) to reach the purpose. They reacted with amphetamine enantiomers to form diasteromeric pairs, which possess some diffeences in physical and chemical natures and could be separated by GC/MS. The paper examined in detail some fectors such as the solvents, chiral reagent amounts, reaction time,temperature,etc. on the effect of chiral derivatization. Some enantiomers of amphetamine (Am),N-methylamphetamine(MAm),3,4-methylenedioxyamphetamin (MDA), 3,4-methylenedioxy-N-methylamphetamine (MDMA), 3, 4-methylenedioxy-N-ethylamphetamine ( MDEA ) and N-methyl-1-( 3, 4-methylenedioxy )-2-butanamine (MBDB) were well separated each other.