To study the preparation and quality standard of the standard decoction of paeonia lactiflora.Methods:The standard decoction of paeonia lactiflora was preparated with water by using standardization method and the content of peoniflorin was determined by UPLC-DAD.Then calculate the transfer rate,the rate of extractum and carry on the research of fingerprint.Results:The content of paeoniflo-rin in 10 batches of standard decoction of paeonia lactiflora is 1.69~2.60 mg/mL，the transfer rate is 60.47%~85.16%，the average transfer rate is 71.62% and the standard deviation is 8.74%.The rate of extractum is 19.00%~26.50%，the average yield is 21.89% and the standard deviation is 2.51%.There were 11common peaks，5 of which were identified，including oxypaeoniflorin，catechins,albiflorin，paeoniflorin and benzoylpaeoniflorin.Conclusion:The method is simple with good repeatability，and it can be used to study the preparation of the standard decoction of paeonia lacti-flora.