Abstract: Objective To investigate the mechanism of antagonistic effect of Cinobutacini injection（CINO） on multidrug resistance (MDR) of human hepatocellular carcinoma in protein expression.Methods Human hepatocellular carcinoma 5-FU resistant cell line were cultured in vitro.The cytotoxicity and the antagonistic effect of Cinobutacini injection on MDR was detected by MTT. The differential expression protein between Bel-7402/FU cells and Bel-7402/FU cells treated with 0.26μg/L CINO were detected by 2-DE and MS . The differential expression of protein FAK,CRT and TMOD3 were detected by westernblot to confirm the results of 2-DE and MS .Results The 50% inhibitory concentration(IC50) as to Bel-7402/FU cells was 0.66μg/L。0.08、0.16、0.32μg/L CINO reversed the MDR by1.56、2.18、2.99 folds respectively . there are 13 protein spots down -regulated and 1 protein spot up-regulated in Bel-7402/FU cells treated with CINO，westernblot comfirmed that portein FAK， CRT and TMOD3 were down-regulated in Bel-7402/FU cells by CINO，they were in accordance with the result of 2-DE and MS . Conclusion CINO can effect the expression of proteins related to MDR ,so as to reverse the MDR of human HCC cells.

Key words: Key words: CINO, HCC , MDR, 2-DE