The　Ru-Ti-Ir-Ta　quaternary　oxide　titanium　anode　coatings　were　prepared　by　thermal　decomposition.　The　phase　structures,　crystal　sizes,　element　distributions,　microstructures　and　morphologies　of　titanium　anode　coatings　were　analyzed　by　means　of　XRD,　SEM,　EDX　and　HRTEM.　The　results　show　that　when　heat-treated　at　500°C,　the　main　phases　in　the　coating　are　rutile-type　TiO2-based　solid　solution　(Ti,　Ru,　Ir)O2　and　IrO2-based　solid　solution　(Ir,　Ti,　Ru)O2　in　a　form　of　quadrangular　prism,　and　their　grain　sizes　are　about　15　nm　and　8　nm,　respectively.　The　titanium　anode　coating　has　distinctly　dry　cracked-mud　in　morphology.　The　coating　contains　primary　cracks　and　secondary　cracks.　Comparatively,　when　heat-treated　at　700°C,　the　main　phases　in　the　coating　are　similarly　to　those　at　500°C,　their　grain　sizes　are　about　18　nm　and　12　nm,　respectively.　However,　there　exits　a　few　RuO2-based　solid　solution　(Ru,　Ti,　Ir)O2　particles　whose　sizes　are　29　nm.　All　of　the　grains　take　a　form　of　quadrangular　prism.　The　titanium　anode　coating　has　the　dry　cracked-mud　in　morphology,　and　contains　primary　cracks,　secondary　cracks　and　third　cracks.　At　the　edge　of　the　secondary　cracks,　Ir-and　RuO2-based　solid　solutions　(Ir,　Ti,　Ru)　and　(Ru,　Ti,　Ir)　O2　are　deposited.