The microkinetics of H2S removal by ZnO desulfurizer in the presence of 7 different gas atmospheres were studied by thermogravimetric analysis. Experiments were carried out with ZnO powder of 100-120 mesh at temperatures from 473 K to 563 K. The experimental data was correlated using an improved shrinking core model. Kinetic parameters in different gas atmospheres were estimated. It was found that there existed a compensation effect in H2S removal process by ZnO.