[Problems] To provide a novel taxane derivative which can release the medicinal substance in a bioenzyme-independent manner, is expected to have an effective therapeutic efficacy, and has a water-solubility. [Means for Solving Problems] Disclosed is a polymer conjugate of a taxane, which comprises a polymer having a polyethylene glycol moiety and two or more succinic acid monoamide moieties and a taxane, wherein a carboxylate group in the polymer and an alcoholic hydroxyl group in the taxane are bound to each other via an ester bonding.