Carbon dioxide reforming of methane over different semi-cokes (Hongce lignite, Shenmu bituminous coal and Jincheng anthracite) is being investigated at atmospheric pressure, temperature of 800-1000 degrees C, CH4/CO2 ratios of 3:1-1:3 and gas solid contact times of 0.11-1.76 min using a fixed-bed reactor. The semi-cokes still shows stable catalyst activity after 480 min of reaction. The results show that the catalyst activity of the semi-cokes was lower with increasing coal rank. The order of the catalyst activity is Hongce lignite semi-cokes > Shenmu bituminous coal semi-cokes > Jincheng anthracite semi-cokes. This is somewhat related to the content of the functional groups of the semi-cokes. The analysis for the surface structure of the semi-cokes before and after the reforming reaction shows that the C=O and -NH2, etc., functional groups on the surface of the semi-cokes participated in the reforming reaction, the coal rank and the BET are the main factors which influenced the catalyst performance, and the functional groups on the surface of the semi-cokes and the types and amounts of alkaline metals have a certain type of influence on the activity of the reforming reaction. (C) 2013 Elsevier B.V. All rights reserved.