CH4-CO2 reforming is of rapid growing interest for reasons of the continuous decrease of petroleum resources and the emphasis on the environmental situation for greenhouse gas mitigation. Plasma technology is considered to be one of potential ways for CH4-CO2 reforming. This paper presents an overview of CH4-CO2 reforming by cold plasmas and thermal plasma. The evaluations for their performances and the key factors in different plasmas are given. In particular, the attention is focused on how to achieve higher conversions at high feed-gas flow rate, so as to lessen the energy consumption in the process by plasma to meet the requirements of industrial application. To obtain the aim, three key factors, electron density, plasma temperature and reactor configuration related to the process are emphasized. Considering the current status of CH4-CO2 reforming by plasma, there is an opportunity to improve the energy conversion efficiency and the treatment capacity of the process by optimizing both plasma form and reactor design in future work. (C) 2010 Elsevier Ltd. All rights reserved.