The incorporation of a phenylboronic acid group has appeared as an attractive strategy to build smart drug delivery systems. Here, we report novel synthesis of phenylboronic acid-functionalized copolypeptides based on an L-boronophenylalanine Ncarboxyanhydride (BPA-NCA) monomer and their application for robust co-encapsulation and responsive release of dual anticancer drugs. By employing different poly(ethylene glycol) (PEG) initiators and copolymerizing with varying NCA monomers, linear and star PEG-poly(L-boronophenylalanine) copolymers (PEG-PBPA, star-PEG-PBPA), PEG-poly(L-tyrosine-co-L-boronophenylalanine) [PEG-P(Tyr-co-BPA)], PEG-poly(L-lysine-co-L-boronophenylalanine) [PEG-P(Lys-co-BPA)], and PEG-poly(β-benzyl-L-aspartateco-L-boronophenylalanine) [PEG-P(BLA-co-BPA)] were obtained with controlled compositions. Interestingly, PEG-PBPA selfassembled into uniform micellar nanoparticles that mediated robust co-encapsulation and hydrogen peroxide (H 2 O 2 ) and acidresponsive release of dual antitumor drugs, curcumin (Cur) and sorafenib tosylate (Sor). These dual drug-loaded nanoparticles (PBN-Cur/Sor) exhibited a greatly enhanced anticancer effect toward U87 MG-luciferase glioblastoma cells. The facile synthesis of phenylboronic acid-functionalized copolypeptides from BPA coupled with their robust drug loading and responsive drug release behaviors make them interesting for construction of smart cancer nanomedicines.