Poly(ethyleneimine) (PEI) loaded hierarchical porous silica monolith has been developed as a recycle H2S sorbent at low temperature. The sorbent was characterized by N-2 adsorption, scanning electron microscope, transmission electron microscope, Fourier transform infrared spectra, and activity tests. The effects of the amount of PEI loading, the operating temperature, and the PEI polymerization degree on H2S removal were studied. The sorbent demonstrated a large H2S breakthrough capacity of 1.27 mmol of H2S/(g of sorbent) at 22 degrees C, which is about 60% larger than that of PEI-loaded SBA-15 or MCM-41 sorbent. The optimal PEI loading is 65 wt %, and the most ideal PEI molecular weight is 600. As the decrease of the temperature, the sorption performance of the sorbent increases greatly. There are two important factors affecting the performance of H2S sorption: the amount of available PEI in the sorbent and the interaction between H2S and amine functional groups of PEI. In addition, the developed sorbent can be regenerated easily at 75 degrees C, and it exhibits excellent regenerability and stability. These results indicate that PEI-loaded hierarchical porous silica sorbent will be promising for removing H2S in the future.