Objective: Comparative study on stability of tanshinone emulsion and tanshinone freeze-dried emulsion. Method: Appearance of tanshinone emulsion and tanshinone freeze-dried emulsion and the content of tanshinone and reconstitution of freeze-dried emulsion were investigated by influential factors test and long-term sample test. Result: System stability of tanshinone emulsion had significantly reduced in 25 ℃ long-term sample test and thermal cycling test;The content of tanshinoneIIA was reduced to varying degrees in 4

25 ℃ long-term sample test and high temperature and light test.System stability of tanshinone freeze-dried emulsion showed good in long-term sample test and influential factors test;The content of tanshinoneIIA was reduced to varying degrees in 25 ℃ long-term sample test and high temperature and light test

but reduced degree was lower than that of tanshinone emulsion in tha same conditions. Conclusion: Tanshinone freeze-dried emulsion showed significantly better than tanshinone emulsion in improving stability of emulsion system and tanshinoneIIA.