In this paper, we have proposed a novel integrated gasification combined cycle (IGCC) system with steam injected H-2/O-2 cycle and CO2 recovery. A new evaluation criterion for comprehensive performance of the IGCC system has also been presented. The thermodynamic characteristics, environmental and comprehensive performance of the new system have been investigated based on comparison of different IGCC systems with O-2/CO2 cycle. The promising results show the new system has less energy penalty for separating and recovering CO2, an efficiency decrease of less than 1 percentage point. The ratio of CO2 penalty price to fuel price is an important factor influencing the comprehensive performance of this system. The performance of the IGCC with O-2/CO2 cycle and syngas separation is better than that with the simple semi-closed O-2/CO2 cycle. The above research achievements will provide valuable information for further study on IGCC systems with low CO2 emission. (C) 2003 Elsevier Ltd. All rights reserved.