PLA-b-PEO-b-PLA triblcek copolymers with different compositions were prepared by ring-open polymerization using OH-capped PEO as macminitiatom．The“crew-cut”aggregates of PLA-b-PEO-b-PLA triblock copolymers in aqueous media were fabricated by dropping water into block copulymer solutions in common solvents．The surface morphology and micro-viscoelasticity of aggregates cast on mica sheets from colloids were investigated by scanning probe microscopy(SPM)．It was observed that the micelles with a diameter of about 45 nm were formed and oranized into relatively single layer on mica surface．Interstedly

inhomogeneity of surface modulus appeared as the water of colloids evaporated．The top of aggregates had relatively higher modulus than that of the peripheral parts of aggregates．The changes of environments of aggregates from polar water to unpolar air on mica sheets were suggested to be responsible for the surface modulus inhomogeneity．In addition

the experimental data showed that the sizes of aggregates measured from dynamic light scattering were greatly larger than those from SPM observations．At the sanle time

increasing the initial concentration of copolymers in common solvents resulted in the increase ofaggregate sizes and higher polydispersities.