Cancer-multidrug resistance (MDR) is recognized as one of the barriers to the treatment of advanced hepatocellular carcinoma (HCC). We aim to inhibit ABCB1 overexpression observed in HCC-MDR phenotypes with N-acetylgalactosamine (GalNAc)-conjugated antisense oligonucleotides (ASOs). In this study, three ASOs (GalNAc-ASO1, GalNAc-ASO2, and GalNAc-ASO3) targeting ABCB1 mRNA and a scrambled-negative control (GalNAc-ASO4) were designed. Simulations of molecular docking were performed to determine the inhibitory efficacy of ASOs. GalNAc C3 phosphoramide ligand was added to the 5'-end of the ASO sequences, and phosphorothioate modifications were added to the DNA backbone. HepG2 cells were directly treated with different doses of GalNAc-ASOs conjugates. To evaluate the inhibitory effect of GalNAc-ASOs conjugates, the protein level of ABCB1 was measured by western blotting. The cell viability assays of GalNAc-ASO4 conjugates on HepG2 were evaluated by colorimetric-MTT and fluorometric-resazurin assays. Varying scrambled-negative control concentrations were applied to HepG2 for assessment of the cytotoxic effect of GalNAc-ASO4 conjugates, and it had no cytotoxic effect on cell viability up to 144 h. GalNAc-ASOs concentrations reducing ABCB1 protein expression after 72 h were detected by western blot. ASOs conjugated with the GalNAc ligand, which specifically targets the liver by binding to asia-loglycoprotein receptors in hepatocyte cells, have the potential to increase the effect of anti-cancer therapies by reducing ABCB1 protein expression through gymnotic delivery to cells.