Objective: To study on stability of active ingredients from Rheum officinale in concentration and drying process. Method: Taking active ingredients from extraction fluid of R. officinale as studying target

samples were taken at different time points in concentration and drying progress

change trends of relative content was determined by HPLC. Result: The relative content of active ingredients were degraded greater degree after concentrated 1 h in process of heating at 70 ℃

its reduction is not obvious after concentrated 2 h by comparing with 1 h

but after concentrated for 3 h

the relative content reduced significantly; At 70 ℃ vacuum drying process

active ingredients were in large degree of degradation after drying 2 h

the change of content was small after drying 3 h by comparing with 2 h

general trend was relative stable

the content of active ingredients was less affected in drying process.Sennoside D decomposed easily in heating. Conclusion: During in process of concentration and drying at 70 ℃ vacuum for extraction fluid from R. officinale

concentration time should be controlled within 2 h

components were stable in drying time for 3 h.