Objective:To study the solubilization effect of 2-hydroxypropyl-?-cyclodextrin(2-HP-?-CD) on anethol trithione and the complexation of anethol trithione with 2-HP-?-CD.Methods:On the basis of single factor experiment,the drug complexed rate was adopted as the index,to study the effects of factors like host-guest molar ratio,alcohol concentration,stiring rate and stiring time on the techniques of preparing anethol trithione-2-HP-?-CD;the inclusion complex was identificated and solubility was detected by diferential scanning calorimeter(DSC) methods.Results:2-HP-?-CD can obviously enhance solubility of anethol trithione.Conclusion:The solubility of inclusion complex increased by 460 times when it was included by 2-HP-?-CD.