Objective: To investigate solubilization effect of compatibility of Glycyrrhiza uralensis-Baphicacanthus cusia. Method: Compatibility of G. uralensis and B. cusia

glycyrrhizic acid and indigo(indirubin)

citric acid and B. cusia

the content of indigo and indirubin in samples were determined by HPLC. Result: When B. cusia was compatible with raw and fried G. uralensis

the content of indigo and indirubin in solution were increased significantly

but they were about 30% lower in fired G. uralensis than raw one;glycyrrhizic acid ammonium salt mixed directly with indigo and indirubin respectively by proportion

the content of them had significantly increased

with improving about 4~8 times

the best proportion was 2∶1;different proportion of citric acid was compatible with B. cusia

the content of indigo and indirubin in solution showed no significant change. Conclusion: Compatibility of B. cusia and G. uralensis could achieve purpose of solubilization

glycyrrhizic acid played a major role

it could provide a theoretical basis for compatibility application of TCM.