A method was developed to synthesize amphiphilic poly(ε-caprolactone)-b—poly(ethylene glycol)(PCL—b-PEO)block copolymers with well—defined structure and with functional antino end-group connected to the PEO block．The molecular weight

composition and chain structure of the resultant copolymers were characterized by GPC and 1H—NMR．The microspheres of the copelymers were prepared by W／O／W double emulsion solvent evaporation method．The analysis results by confocal laser scanning microscopy indicate that the anlino groups are distributed dominantly on the surface of microspheres due to the hydrophilic property of amino groups and the formation process of microspheres in aqueous phase．The surface morphology of microspheres could he regulated by changing the composition of block copolymers．The results of this work indicate that the surface properties of the miemspheres can be controlled by polymer chain structure

and that the microsoheres with amino group located on the surface can be further conjugated with peptide such as RGD．Therefore

these microspheres are promising materials as microcarriers for promoting cell growth．