Abstract:Objective: To explore the effect of compound decoction on notoginsenosides in Panax notoginseng. Method: Notoginsenoside R1, Rg1, Re, Rb1 and pH were used as the parameters to investigate the changes on the content of notoginsenosides in different compound extractions by heating for two hours and their correlation with pH. Result: When the pH values of solution of P. notoginseng with Fructus ligustri, P. notoginseng with Eupolyphaga seu steleophaga, P. notoginseng with Pheretima asiatica, and Zhitangjiang Fang (free of Hirudo) were rept higher than 5.7, the reserved rate (RR) of notoginsenside were higher than 90%; When the pH values of decoetion of P. notoginseng with Salvia miltiorrhiza, P. notoginseng with Paeonia lactiflora, P. notoginseng with Platycodon grandiflorum, P. notoginseng with Arctium lappa were kept 4.5-5.5, their RR of notoginsenside were 60%~85%; When the pH values of the decotction of P. notoginseng with Hirudo nipponica was decreased to 3.4, its RR of of notoginsenside was 38.4%; When the pH values of Zhitangjiang Fang extraction was regulated by 0.1% NaOH solution to pH 6.3, and the RR of notoginsenside increased to 97%. Conclusion: The pH of other Chinese herbal medicines extraction with P. notoginseng compound is a critieal effect on the stability and yields of notoginsensides.