Abstract: The dimethyl ether (DME) carbonylation reaction over mordenite is greatly affected by the mass transfer process. In this research, hierarchical mordenite catalysts were synthesized and characterized to investigate the influence of mesopores on the structure, mass transfer and catalytic performance. The results show that the medium-strong acid sites decrease while strong acid sites increase over the hierarchical samples. The introduced mesopores can significantly improve the mass transfer efficiency and the carbonylation performances are markedly improved on the hierarchical samples. In addition, the polymerization degree of coke deposition on the deactivated samples decreases although the coke amount increases. Excessive usage of mesopore templates can damage the structure of the MOR catalysts, thus leading to the loss of acid sites and the decrease in catalytic performance.