CaDyAlO4　(CDA)　crystals　with　dimensions　of　Φ　25　×　28　mm3　were　grown　by　the　Czochralski　method.　The　presence　of　a　small　amount　of　oxygen　in　the　growth　atmosphere　will　cause　the　coloration　of　CDA　crystal,　and　correspondingly　reduce　the　transmittance　in　the　range　of　400–730　nm.　Rietveld　structural　refinement　of　XRD　patterns　revealed　a　slight　difference　in　the　unit　cell　parameters　of　the　brown　and　yellow-green　CDA　crystals.　The　angular　and　temperature　dependencies　of　the　magnetic　susceptibility　were　measured,　indicating　that　CDA　crystal　has　remarkable　magnetic　anisotropy　and　abnormal　magnetic　behavior　in　the　a　and　c　direction　below　150　K.　Faraday　rotation　characteristics　of　CDA　crystal　were　investigated　at　room　temperature.　Verdet　constant　of　CDA　at　500–700　nm　band　is　about　1.1　times　as　large　as　that　of　TGG,　but　only　0.69　fold　of　that　for　isostructural　CaTbAlO4　(CTA).　Based　on　the　Van　Vleck-Hebb　theory,　the　effective　transition　wavelength　and　probability　of　three　crystals　were　calculated　and　compared.　The　absorption　and　magnetic　circular　dichroism　spectra　(MCD)　of　4f-4f　transitions　in　Dy3+　ions　in　CDA　were　studied.　©　2020　Elsevier　B.V.