This research performed the gasification kinetics of three Shenhua coal under CO2 atmosphere using isothermal thermogravimetry. Results showed that isothermal gasification curves for three different coal samples revealed different gasification behaviour. Among the eleven kinetic models, A2 was the most suitable one to describe the gasification kinetics of three coal samples, because it can reproduce the experimental data very well with reasonable correlation coefficients. The activation energy for sample A, B and C were 95.9, 79.1, and 69.4 kJ mol-1, respectively. The activation energy decreased with the increase of the particle size. The compensation relationship was observed between activation energy and frequency factor, and the mathematical expression was lnA=0.1041 E+0.54028 with the correlation coefficients of 0.999.