The present document relates to a manufacturing method for pH-sensitive graft polymer micelles and a polymer micelle-type pharmaceutical composition containing the graft copolymer. The pH-sensitive graft copolymer micelles are usable as various markers and contrast agents for various molecular images for the diagnosis and treatment of diseases and a carrier for delivery of various medicines according to disease. The pH-sensitive graft copolymer forms micelles that can be used in target-oriented diagnosis and medicine release according to changes in the pH of a body. The polymer micelles are provided by inducing a graft copolymer of poly(β-amino ester) compounds which has a solubility in water depending on pH but is incapable of forming the micelles due to a self-assembly phenomenon, and hydrophilic poly(ethylene glycol) compounds.