Recently,oxidation-responsive polymers have been demonstrated to be promising for various biomedical applications[1].Among them,polymers containing phenylboronic acid/ester have attracted much attention due to that they can be selectively and quickly oxidized by H2O2 at biological relevant level[2].In this work,a phenylboronic ester-linked Y-shape polymer was synthesized via sequential Passerini reaction and thiol-yne click reaction (Fig.1).