In this work, we performed density functional calculations to examine the molecular adsorption states of thiophene on beta-SiC(0 0 1)-2 x 1 surface. A number of possible adsorption geometries are considered into two groups as the polymeric thiophene chain and the individual molecules covalently bonded onto the surface. The results show that the polymeric chain on the surface is the less stable adsorption case and individual arch like adsorption case structure is more stable than others. In all adsorption cases, the adsorbed SiC surfaces are characterized as different semiconductors. (C) 2011 Elsevier B.V. All rights reserved.