With　ab-initio　calculations,　the　geometrical　structure,　electronic　band　structure,　optical　and　thermodynamic　properties　of　pure　and　Ce　doped　La2Zr2O7　are　calculated.　Doping　Ce　at　Zr　site　modified　the　intrinsic　band　gap　of　La2Zr2O7.　However,　increasing　the　Ce　doping　concentration　has　no　considerable　effect　on　the　band　structure.　With　the　increase　in　Ce　doping　concentration,　the　absorption　spectra　of　the　doped　La2Zr2O7　is　shifted　to　higher　wavelengths　and　the　peaks　intensity　is　reduced.　Some　of　the　peaks　associated　with　the　intrinsic　La2Zr2O7　are　disappeared　and　new　peaks　are　introduced　in　3.40%　Ce　doped　La2Zr2O7.　Perturbations　in　the　phonons　density　of　states　are　reduced　with　the　increasing　Ce　doping　concentration.　The　La16Zr13Ce3O56　system　with　3.40%　of　Ce　doping　provided　the　most　stable　phonons　curve　among　the　simulated　systems.　Interesting　behavior　is　observed　in　the　thermal　conductivity　of　the　doped　models　with　the　increasing　temperature.　The　thermal　conductivity　of　La16Zr15CeO56　model　increases　compared　to　the　pure　La2Zr2O7.　However,　further　increase　in　the　Ce　doping　concentration　drastically　reduced　the　thermal　conductivity　values　in　the　range　373-1673　K.　The　La16Zr13Ce3O56　system　(3.4%　Ce)　provided　the　lowest　thermal　conductivity　attributed　to　the　high　concentration　of　point　defects　affecting　the　phonon　scattering.　©　2019　IOP　Publishing　Ltd.