Abstract: The ethanolic extracts of 100 common traditional Chinese drugs, which are widely used in many prescriptions in treatment of cancer in China, were screened for MDR of KBV200 cell line in vitro with MTT method. The result showed 9 extracts having MDR reversal activity. They were the extracts of Fructus Lagenariae Sicerariae, Radix Glycyrrhizae, Poria, Herba Andrographitis, Radix Sophorae Tonkinensis, Caulis Mahoniae, Folium Artemisiae Argyi, Rhizoma Curcumae, Fructus Cnidii. Other 5 extracts showed cytotoxic on KBV200 cell line.

Key words: Traditional Chinese drugs, Traditional Chinese drugs, Reversing MDR, Reversing MDR, Screening, Screening, In vitro, In vitro