Abstract: Capsulated super-fine disperse dye blue 60 was prepared by phase separation method with Poly(St-MA) as wall material. The effects of preparation conditions on particle size and size distribution were investigated. The results illustrated that amount of Poly(St-MA), amount of disperse dye, dropping speed of phase separation agent and dispersing time had great influence on the size of prepared disperse dye. The optimal prepared condition was that the ratio of Poly(St-MA) and disperse dye was 1:5, dropping speed of phase separation agent was 7mL/min, dispersing time of 1.5h. FTIR and wettability of disperse dye before and after encapsulation showed that the Poly(St-MA) was encapsulated on the surface of disperse dye. DLS showed the prepared disperse dye was with small particle size, narrow size distribution.