Liquid phase RTD curves were investigated in classical fixed and fluidized bed regimes with high density particles. The effect of liquid velocity was studied on bed hydrodynamics. Using an impulse tracer injection technique in a column of 5 cm inner diameter and 1.2 m height, liquid RTD, mean residence time (MRT), axial dispersion coefficient (ADC) and vessel dispersion number (ND) were determined. ADC increases with liquid superficial velocity. It varied from 4.63 to 20.7 cm2/s for the particle Reynolds number of 43 to 279, respectively. The experimental results show that the hight density particles cause less ADC than the low density particles at an identical Reynolds number.