This work focuses on the investigation of the catalyst post-treatment in the liquid phase methanol synthesis process. The novel post-treatment process, using carbon dioxide, has been developed and experimentally proven to be effective not only in maintaining the initial catalytic activity over a long period of usage but also in improving the mechanical and chemical strength of the catalyst. It was also found that the role of ZnO in the catalytic reaction, if any, can be nicely replaced by ZnCO3.