Abstract: The preparation method of ZnO nanoparticales,sedimentation dispersion method,was developed with low cost,large yield,diameter controlled,non aggregation and high quality by drawing lessons from some of the advantages about traditional sedimentation method of zinc oxide powder and by proceeding essential improvement.By used ZnSO4,NH4HCO3 and adding surface active agent to solution before reaction into the ZnCO3·2Zn(OH)2·4H2O,the forerunner of ZnO,was prepared with non aggregation.After the forerunner washed by water with surface active agent,filtered and dried,heated 0.5-1.5h at 380-550℃,the ZnO nanoparticales was made with less aggregation and diameter smaller than 60nm.The ZnO nanoparticales with non aggregation, average diameter 35.6nm was manufactured by grinding the less aggregative ZnO nanoparticales two hours with alcohol.On the basis of experiments,the principles of aggregation and dispersion of ZnO nanoparticales were analyzed.