AbstractAmino polysiloxanes (APSs) with different amino values and amino types were synthesized and applied to cotton fabrics. Softening and smoothening properties of the fabrics treated with APSs were investigated and evaluated by measuring wrinkle recovery angles and friction coefficients, and the morphological features of the APSs adsorbed onto cellulose substrate films were characterized by atomic force microscope (AFM). The results indicate that the amino values and amino types of the APSs have a significant impact on the softening and smoothening properties of the fabrics. APSs with relatively high amino values exhibit superior smoothening property, while APSs with moderate amino values exhibit excellent softening property. Compared to the traditional softener N‐β‐aminoethyl‐γ‐aminopropyl polydimethylsiloxane (APS‐1), the new amino type softeners γ‐piperazinylpropyl polydimethylsiloxane (APS‐2) and N‐γ'‐dimethylaminopropyl‐γ‐aminopropyl polydimethylsiloxane (APS‐3) gave better fabric performance, whereas aminopropyl polydimethylsiloxane (APS‐4) and N‐cyclohexyl‐γ‐aminopropyl polydimethylsiloxane (APS‐5) gave unsatisfactory fabric performance. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011