Low temperature plasma made some modifications of pellet materials (activated alumina and haydite) placed between electrodes. It altered the characteristics of pellets after discharge, such as the pellet surface element proportion, binding energy, specific surface area, pore volume and pore size. The activated alumina surface parameters of specific surface area, pore volume and pore size increased after discharge, which was good for catalytic activity. The original pores on haydite surface were destroyed, and bigger holes were formed. Activated alumina would be polarized when placed between discharge electrodes, which enhanced the electric field intensity. Due to the effect of plasma, the solid pellet surface was modified, which was useful for pellet catalysis in application.