Abstract: In order to reveal the softening mechanism of functional polysiloxanes, the film morphology and characteristics of the polysiloxane bearing pendant long carbon chain alkyl groups were investigated by atomic force microscope(AFM),scanning electronic microscope(SEM) and other instruments.Experiment results indicate that the polysiloxane can form a hydrophobic and coarse silicone film in oriented arrangement on the surface of fibers or silicon substrate.And in(2 μm~2) scanning field,the average roughness of the film reaches(0.199 nm.)