Objective: To investigate thermal stability of ginsenosides Rg1

ginsenoside Rb1 and notoginsenoside R1 in water decoction of Notoginseng Radix et Rhizoma. Method: Contents of ginsenosides Rg1

ginsenoside Rb1 and notoginsenoside R1 were determined by HPLC

acetonitrile(A)-water(B) system was taken as mobile phase with gradient elution(0-12 min

19%A;12-60 min

19%-36%A)

detection wavelength was 203 nm.Effects of heating time and temperature on contents of index components from water decoction and mixed standard solution were investigated by single factor tests. Result: When heating time came to 12 h

ginsenoside Rg1

ginsenoside Rb1and notoginsenoside R1 had different degree of degradation

and they degraded rapidly when temperature increased.It's reduced to 30%

50%

30% of the initial content at 100℃;While contents of these three kinds of saponins in mixed standard solution was almost no conversion. Conclusion: Contents change of three kinds of saponins in water decoction of Notoginseng Radix et Rhizoma was not primarily caused by temperature

but it may be due to effect of specific substances in Notoginseng Radix et Rhizoma.