Abstract: To establish an extraction method for trans-chrysanthemic acid using lipophilic L-tartaric esters and hydroxypropyl-β-cyclodextrin as chiral selector,the distribution of trans-CA enantiomers was examined in aqueous methanol solution containing HP-β-CD,1,2-dichloroethane organic solution and lipophilic L-tartaric esters.The influences of the concentrations of L-tartaric esters and HP-β-CD,the length of alkyl chain of L-tartaric esters,pH and the concentration of aqueous methanol solution on the partition coefficient(K) and separation factor(α) of trans-CA were investigated.The experiment results show that the complex formed by L-tartaric esters with S enantiomers is stabler than that by L-tartaric ester with R enantiomers.With the increase of the concentration of L-tartaric esters,K and α increased;with the increase of the concentration of HP-β-CD,K and α increased firstly,and then decreased,K and α were the highest when the concentration of HP-β-CD was 3 mmol/L.The length of alkyl chain of L-tartaric esters has great influences on K and α.With the increase of pH,K and α decreased;with further increasing the concentration of methanol,K and α decreased,K and α were the highest when the concentration of methanol was 10%.