Objective To investigate the relationship between the expression of β-catenin and drug-resistance mechanism of choriocarcinoma according to the expression of β-catenin in JEG-3 cells (human choriocarcinoma cell line) and drug resistant JEG-3/VP16 cells.Methods The mRNA and protein expressions of β-catenin were analyzed with reverse transcription-polymerase chain reaction(RT-PCR) and Western blotting.Flow cytometry was used to determine the percentages of β-catenin-positive cells in the two choriocarcinoma cell lines.Results Both drug resistant choriocarcinoma cells and drag sensitive cells were found to express β-catenin; but the expression of β-catenin mRNA (1.43 ±0.24) and protein(1.49 ±0.17)in drug resistant choriocarcinoma cells was found much higher than that in drug sensitive cells(0.65 ±0.14,0.66 ±0.16,P ＜0.01).And according to detect by flow cytometry,we found the number of β-catenin-positive cells in JEG-3/VP16 cells [(40.13 ±5.17) ％] was much more than that in JEG-3 cells [(13.15 ± 1.48) ％,P ＜ 0.01].Conclusions β-catenin was highly expressed in the drug resistant choriocarcinoma cell line (JEG-3/VP16).It indicates β-catenin might be involved in the drug resistance mechanism of choriocareinoma.