Objective: To investigate influence of hydroxypropyl-β-cyclodextrin on solubility of ginsenoside Rg1. Method: The content of ginsenoside Rg1 was determined by HPLC

orthogonal test was used to study on concentration of hydroxypropyl-β-cyclodextrin、temperature and stirring time

single factor test was used to analysis the influence of pH to solubility of ginsenoside Rg1

and investigated freeze-thaw stability of samples prepared in these conditions; Result: Optimum conditions for hydroxypropyl-β-cyclodextrin improving solubility of ginsenoside Rg1 were as follows:concentration of hydroxypropyl-β-cyclodextrin 40%

temperature 40 ℃

stirring time 12 h.When pH was 7

solubility of ginsenoside Rg1 was 353.20 g·L-1. Freeze-thaw stability of samples was good. Conclusion: Solubility of ginsenoside Rg1 had greatly improved by using hydroxypropyl-β-cyclodextrin.