Abstract: In order to research H₂S adsorption in coal, eight coal samples of three kinds of different coal ranks were collected, then isothermal adsorption experiments under the condition of pressured-mercury and water balance were conducted respectively. The results showed that the isothermal adsorption curve of H₂S adsorption on coal fits Langmuir model, which was divided into fast rising phase, slow rising phase, and equilibrium phase. The greater percentage of the smaller pores (transition pores and microspores), the higher degree of coal metamorphism and pressure, and the better adsorption of H₂S on coal.