In order to investigate the coal gasification characteristics at elevated pressure, Pressurized Drop Tube Furnace apparatus were designed and manufactured. It can be operated at pressures up to 25atm, and temperatures up to 1500℃, with variable reaction time, particle feeding rate, and with inert and various oxidizing atmospheres. PDTF experiments using varied temperature(1000-1400℃), oxygen/coal ratio(0.0-1.4g/g), steam/coal ratio(0.0-0.4g/g) and pressure(1-15atm) with Indonesian subbituminous coal (Roto coal) were performed in order to investigate the effects of these experimental parameters on global gasification characteristics at elevated pressure. The results shows that the gasification at elevated pressure is more profitable than that at atmospheric pressure considering the carbon conversion and cold gas efficiency. The oxygen/coal ratio at which maximum cold gas efficiency was appeared ranged from 0.5 to 0.7g/g. As the pressure increased, the volume of mass loss by heterogeneous reaction increased but the volume of mass loss by pyrolysis decreased relatively. Results showed that within the experimental conditions covered in this tests, the relationships between the steam/coal ratio and gasification characteristics were affected more by temperature than by pressure. Only at sufficiently high temperature, increase of the steam/coal ratio caused the increase of the gas phase products yield; CO, $H_2$ and $CO_2$. The $n^th$ order rate equation ($R=KP^n$)which is commonly used to describe the kinetics of heterogeneous reaction is found inappropriate for describing the heterogeneous reaction at reaction conditions where the total pressure changes.
