Nanoparticles (NPs) are widely used in various applications. NPs agglomeration will alter its physical andchemical properties. To overcome this, dispersion of NPs by beads mill is desirable to achieve good dis-persion stability. Experimental works to investigate the dynamics of the system is complicated and highcost. On the other side, numerical models offer alternative method inexpensively. In this research, theeffect of impeller rotation speed on the NPs by experimental and simulation study dispersion statewas discussed. Experimental results showed that rotational speed of 2400 rpm could introduce a betterreduction size and dispersion state than that of 1200 and 1800 rpm. Numerical modelling via DiscreteElement Method (DEM) simulation was carried out to study the solid velocity distribution profile duringthe dispersion process. Experimental and simulation results were correlated to investigate the relationbetween the particle size distribution and the particle velocity distribution profile