The　strain　fields　in　a　wafer-bonded　GaAs/　GaN　structure　are　measured　by　electron　backscatter　diffraction　(EBSD).　Image　quality　(IQ)　of　EBSD　Kikuchi　patterns　and　rotation　angles　of　crystal　lattices　as　strain　sensitive　parameters　are　employed　to　characterize　the　distortion　and　the　rotation　of　crystal　lattices　in　the　GaAs-interface-GaN　structure,　as　well　as　to　display　the　strain.　fields.　The　results　indicate　that　the　influence　region　of　the　strains　in　the　wafer-　bonded　GaAs/GaN　structure　is　mainly　located　in　GaAs　side　because　the　strength　of　GaAs　is　weaker　than　that　of　GaN.　The　cross-sectional　image　of　transmission　electron　microscopy　(TEM)　further　reveals　the　distortion　and　the　rotation　of　crystal　lattices　induced　by　strains　systematically.