Highly ordered mesoporous carbon molecular sieves designated as CMK-1 were synthesized using mesoporous MCM-48 silica with various pore diameters as templates. sucrose as a carbon source and sulfuric acid as the carbonization catalyst. The effect of the sucrose-to-sulfuric acid ratio on the structure of the resultant carbon, the effect of the pyrolysis temperature, and the optimum amounts of sucrose for MCM-48 with various pore diameters have been investigated. These results show that the synthesis method can be accurately controlled to obtain the highly ordered mesoporous carbon molecular sieves in a large scale. (C) 2001 Elsevier Science B.V. All rights reserved.