Although sorafenib (SFB) showed improved efficacy and much reduced the side effects in clinical liver cancer therapy, its therapeutic efficacy was still greatly limited due to short half-life in vivo as well as drug resistance. To solve these problems, we developed a novel SFB-loaded polymeric nanoparticle for targeted therapy of liver cancer. This polymeric nanoparticle, referred to NP-SFB-Ab, was fabricated from self-assembly of biodegradable block copolymers TPGS-b-poly(caprolactone) (TPGS-b-PCL) and Pluronic P123 and drug SFB, followed by conjugating the anti-GPC3 antibody. NP-SFB-Ab showed robust stability and achieve excellent SFB release in cell medium. The CLSM demonstrated that the Ab-conjugated NP exhibited much higher cellular uptake in HepG2 human liver cells than non-targeted NP. The MTT assay also confirmed that NP-SFB-Ab caused much greater cytotoxicity than non-targeted NP-SFB and free SFB. Finally, NP-SFB-Ab was proved to greatly inhibit the tumor growth of HepG2 xenograft-bearing nude mice without obvious side effects. Therefore, this NP-SFB-Ab provides a promising new approach for targeted therapy of hepatocellular carcinoma.