Abstract: Morphology and chemical structure of linear polyether block aminopolysiloxane (BPEAS) assembled on the silicon were investigated by atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) and its performance properties on the fabric were studied comparatively. The results indicate that BPEAS can form a film with a nonuniform microstructure, the morphology of which was mainly composed of continuous phase with a nonuniform structure attributed to polysiloxane backbone in BPEAS and clusters of vertical spikes assigned to the aggregation of the polyether groups resulted from water absorption in the air. Roughness analysis of the film surface shows that the root mean square roughness of the film surface is 0.419 nm in 2×2 μm2 scanning region with scale data (SD) of 20 nm. Application experiments results show that the softness of fabric treated by BPEAS has been improved obviously, and the cotton fabric treated by BPEAS exhibited the best performance properties compared with that of N-β-aminoethyl-γ-aminopropyl polydimethylsiloxane (ASO-1) and polyether silicone oil, such as Epoxy / polyether modified silicone oil (CGF).