Abstract: Objective: To evaluate the effect of antisense oligonucleotide(AsODN), which was targeted at LRP gene, on reverting cisplatin-resistance of multidrug-resistant human ovarian cancer cell line OVCAR-3. Methods: The cytotoxicity of LRP AsODN and cisplatin, or comined both of them were assayed by sulforhodanmine B(SRB) method. LRP AsODN was transfected into OVCAR-3 cell by lipofectamine 2000. The expression of LRP was monitored by RT-PCR and Western blot in LRP AsODN transfected and non-transfected OVCAR-3 cells and the apopototic rates of both cells were detected by flowcytometry after having been treaded with cisplatin. Results: The cytotoxity of LRP AsODN was very low when its concentration was under 800nmol/L. The expression of LRP m R N A and protein were inhibited and a positive drug resistance to cisplatin was observed after LRP AsODN was transfected into OVCAR -3 cells. The apopototic rates of LRP AsODN transfected and non -transfected cells were (27.43±2.05)% and (15.43±1.14)% respectively, the difference was statistically significant (P=0.001).Conclusion: Transfection of LRP AsODN could interrupt the expression of LRP and restore drug sen-sitivitv to cisplatin in multidrug-resistant human ovarian cancer cell line OVCAR-3.