Tar steam reforming (TSR) is a very attractive technique for tar removal. It converts high molecular weight hydrocarbons of tar into smaller gas products including H2, CH4, CO and CO2. Preliminary research focuses on simulation of tar steam reforming. It was assumed to be at thermodynamic equilibrium and the calculations were performed using Aspen Plus Program. The simulation results help understand the effect of operating condition and identify suitable operating conditions (reaction temperature, S/C ratio) for the experimental tar steam reforming. Representative tar consisted of C10H8, C7H8, C6H6O and C16H10 whosecompositions varied with temperatures of biomass gasification (700-800 °C). The experimental study of thetar steam reforming reaction was carried out at different temperatures (450-650 °C), S/C ratios (1-5), type of supports (Al2O3, CaO and MgO) and %metal loading of a nickel catalyst (10, 15 and 20 %). The experimental results follow the trends observed from the simulations that the reaction at high temperature and S/C ratio produce more hydrogen content. 20 %Ni/Al2O3 was reported as a suitable catalyst which offered stable and efficiency activity for tar steam reforming.