Abstract: In this paper,the dispersion stability of oolitic hematite ultrafine particles in water was in vestigated . The disperson performanc and mechanisms of some influencing factor such as dispersion mode,dispersion type,dispersion dosage and pH was discussed. Experimental results showed that compasite dispersion mode is better than single machinery or chemical dispersion,(NaPO₃)₆ are effective dispersants for oolitic hematite ultrafine particles in water and the better dispersion performance can be got in pH 6.2.