Abstract: Two disperse dyes were used to color poly(styrene-co-acrylic acid)[P(St-co-AA)]nanospheres at temperatures below the glass transition temperature of the nanoshperes (110.69℃). Then we studied the effect of temperature(75~95℃) and dye concentration (1%~5%) on the dye content adsorbed on the nanopheres. The results show that the higher the dyeing temperature the more the dye stained on the nanospheres. Increasing the dye concentration of dyeing bath results in higher dye contents on the nanospheres. Higher dye contents gave brighter and deeper colors of the nanospheres. The dye contents of the nanospheres colored with disperse blue 2BLN,which has two amino groups and two hydroxyl groups,are lower than the dye contents of the nanospheres colored with disperse red FB,which has one amino group and one hydroxyl group. After being dyed,the nanospheres become very rough and the size increases 23 nm. The cotton fabrics after cationic modification were dyed with the colored nanospheres. The dyed cotton fabrics obtain deep and bright colors with a very small amount of the colored nanospheres.