Abstract: To investigate the enhancement of impregnation of sodium carbonate and relative humidity of the feed on the adsorption of low concentration H2S on activated carbon under anaerobic conditions at ambient temperature, the experiments of dynamic adsorption of hydrogen sulfide on activated carbon and the impregnated one were carried out under different relative humidity. The effect of temperature on adsorption processes was also investigated. The results show that the adsorption equilibrium data were fitted well with the Freundlich Isotherm. Compared with the activated carbon，the BET surface area and the micropore volume of the impregnated ones were reduced slightly while the adsorption capacity of H2S increased. This indicates that H2S reacts with the impregnant on the surface of activated carbon. When relative humidity is increased, the adsorption capacity is evidently enhanced on both of activated carbon and the impregnated one. The equilibrium adsorption capacity decreases and the breakthrough time reduce with the temperature increasing.