Axial dispersion of continuous liquid phase and gas-liquid mass transfer characteristics were investigated in a three-phase inverse fluidized bed with viscous liquid medium. The axial dispersion coefficient of liquid phase(D) increased with increasing gas(U-G) or liquid Velocity(U-L), but decreased with an increase in the viscosity of continuous liquid medium(mu(L)). The volumetric gas-liquid mass transfer coefficient(k(L)a) increased with increasing U-G but decreased with increasing mu(L),while it did not change considerably with increasing U-L : The effects of U-G were dominant in three phase inverse fluidized beds. In the beds of polyethylene particle(relatively heavier particle), the values of D-z and k(L)a exhibited higher values than those in the beds of polypropylene particles(lighter particle). The values of D-z and k(L)a were well correlated in terms of operating variables.