The　thermal　conduction　behavior　of　the　neutron　absorbing　ceramic　boron　carbide　in　the　initial　stage　of　the　irradiation　was　analyzed　and　a　classical　thermal　conduction　model　was　used　to　estimate　the　variation　of　the　thermal　conductivity　in　this　paper.　The　calculated　thermal　conductivity　using　the　model　shows　a　large　degradation　in　the　initial　stage　of　irradiation.　As　the　burnup　increases,　the　thermal　conductivity　turns　to　be　free　of　temperature　dependence.　These　calculated　results　are　consistent　well　with　the　experimental　data　of　thermal　conductivity　of　the　irradiated　boron　carbide,　which　may　suggest　that　the　variation　of　the　thermal　conductivity　of　boron　carbide　is　predominantly　determined　by　the　point　defects　scattering　in　the　initial　stage　of　irradiation.　©　2017　Trans　Tech　Publications,　Switzerland.