In order to extend the application of Mo2C as electric materials, the preparation of RE molybdenum carbide LnxMoyC by means of rare earth co-permeation with (NH4)3[CrMo6O24H6]·7H2O as the precursor and its conductivity were studied. XRD, EDS, XPS and four-probe poles were used to characterize the structure, element content, valences and conductivity of LnxMoyC. Results show that the structure of the prepared LnxMoyC is single hexagonal close-packed (hcp) and some rare earth elements such as Nd, Gd, La and Sm permeated into crystal phase of molybdenum carbide have influence on its conductivity. The conductivity of LNSGMC (La0.00593Nd0.00562Sm0.00502Gd0.00500Mo1.98C ) at room temperature is 4.692×102 S·cm-1, which is 4.6 times higher than the highest value (1.025×102 S·cm-1) by conventional methods. In the range of 289-490 K, it shows metallic conductivity while in 490-550 K range it shows obvious semiconductor conductivity.