Alternative　mechanisms　of　toxic　effects　induced　by　2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD),　instead　of　the　binding　to　aryl　hydrocarbon　receptor(AhR),　have　been　taken　into　consideration.　It　has　been　recently　shown　that　TCDD　reduces　rapidly　the　activity　of　CK2(casein　kinase　II)　both　in　vivo　and　in　vitro.　It　is　found　that　TCDD　has　high　molecular　similarities　to　the　known　inhibitors　of　CK2　catalytic　subunit(CK2　alpha).　This　suggests　that　TCDD　could　also　be　an　ATP-competitive　inhibitor　of　CK2　alpha.　In　this　work,　docking　TCDD　to　CK2　was　carried　out　based　on　the　two　structures　of　CK2　alpha　from　maize　and　human,　respectively.　The　binding　free　energies　of　the　predicted　CK2　alpha-TCDD　complexes　estimated　by　the　molecular　mechanics/Poisson-Boltzmann　surface　area(MM/PBSA)　method　are　from　-85.1　kJ/mol　to　-114.3　kJ/mol　for　maize　and　are　from　-96.1　kJ/mol　to　-118.2　kJ/mol　for　human,　which　are　comparable　to　those　estimated　for　the　known　inhibitor　and　also　ATP　with　CK2　alpha.　The　energetic　analysis　also　reveals　that　the　van　der　Waals　interaction　is　the　dominant　contribution　to　the　binding　free　energy.　These　results　are　also　useful　for　designing　new　drugs　for　a　target　of　overexpressing　CK2　in　cancers.