Abstract: In this experiment,pueraria was extracted from the Vine of Pueraria lobata using ethanol refluxing method.The main influence factors( the extraction temperature,the extraction time,the solid- liquid ratio) of extraction rate were selected from the results of single factor test,the extraction conditions of pueraria were optimized by response surface design,and its stability to oxidizer( reducer) and metal ion was studied.The results showed that the optimum extraction technology was for the extraction temperature 79 ℃,the extraction time was87 min,and the solid- liquid ratio of 1 ∶ 14 g / m L,the extraction rate of pueraria was 2.2515%.The stability results indicated that the pueraria were not affected by H₂O₂ as the oxidizing agent,but the change of the absorbency was caused by Na₂SO₃ as the reducing agent.The stability of pueraria was not affected by Na+and K+,but it was influenced by Cu²⁺.So the storage and use of the pueraria process should avoid contacting with reducing agent and Cu²⁺.