First principles calculations were conducted to investigate the stabilities of six multi-component carbides of Cr7C3 by calculating the cohesive energy and formation enthalpy of them. The theoretical predictions were compared with the experimental results and they were in agreement with each other. The electronic structures of the six carbides were also calculated in order to provide more information about the relationship between the stability and crystal compositions at atomic scale. (C) 2008 Elsevier B.V. All rights reserved.