Abstract: A numerical simulation was carried out to study the heat transfer characteristics of supercritical water in eccentric annular channel using CFX software. SST model which agrees better with the experimental data under supercritical condition was used to study the effect of eccentricity and asymmetry in annular channel. The simulation results show that both the eccentricity of annular channel and the asymmetry of inner tube in annular channel can lead to the asymmetrical distribution of circumferential temperature and velocity. The asymmetrical distribution of circumferential temperature and velocity can also be affected by particular variations of water properties under supercritical condition, which may affect the heat transfer characteristics.