The present invention provides an amphiphilic block copolymer for drug delivery and a controlled release system comprising the same copolymer. The copolymer comprises at least one hydrophilic block and at least one hydrophobic block, wherein the hydrophobic block is selected from the group consisting of acrylates, methacrylates, acrylamides, methacrylamides, vinylethers and their aromatic derivatives, wherein at least one hydrophobic block contains an aryl group, which is bound to the hydrophobic block with a degradable linker. The controlled release system of the invention shows high stability and high drug retention when administered in vivo enabling accumulation and drug release at the site of action.
