〔Abstract〕 Objective To compare the effects of five single drugs of xiaorusanjietang-radix rehmanniae praeparata, paeonia lactiflora, fructus gardeniae, sculellaria barbata and fritillaria thunbergii on the sensitivity of drug resistance to adriamycin resistant human breast cancer cell line MCF-7/ADR. Methods Radix rehmanniae praeparata, paeonia lactiflora, fructus gardeniae, sculellaria barbata and fritillaria thunbergii were prepared and distilled. The freeze-dried powder of each medicine was dissolved into 1 mg/ml liquid storage solution with phosphate buffer saline(PBS). The methyl thiazolyl tetrazolium(MTT) assay was used to determine the non-toxic and lethal dose of each drug to MCF-7/ADR cells. After pretreatment of MCF-7/ADR cells with non-toxic dose as the reverse concentration of drug resistance, adriamycin was added and MTT method was used to detect whether the single drug had a reverse effect on cell resistance. Results MCF-7/ADR was treated with non-toxic low dose(1 μg/ml) and high dose(10 μg/ml), respectively, and no single drug radix rehmanniae praeparata, paeonia lactiflora, fructus gardeniae and sculellaria barbata were observed to reverse cell resistance. However, when treated with fritillaria thunbergii alone, adriamycin had a killing effect(P<0.05), and the dose-dependent reversal effect was observed when combined with adriamycin of different concentrations. Conclusion The single drug fritillaria thunbergii in xiaorusanjietang has a reversal effect on the drug resistance of MCF-7/ADR cells, and the reversal ability is dose-dependent.