(Ba0.5Sr0.5)TiO3　(BST)　coating　was　applied　to　the　etched　aluminum　foils　by　sol-gel　dip-coating　with　(Ba0.5Sr0.5)TiO3　sol　prepared　by　mixing　tetrabutyl　titanate,　barium　acetate,　strontium　acetate,　diethylene　glycol,　acetic　acid　and　distilled　water.　After　annealing　under　500-600degreesC　in　air,　Al2O3-BST　composite　oxide　film　was　formed　on　the　surface　of　the　etched　aluminum　foil　by　anodizing　galvanostatically　in　a　neutral　adipite　and　borate　solution.　The　BST　powders　annealed　under　different　temperatures　were　characterized　by　TG-DTA　and　X-ray　diffraction　(XRD),　and　the　specific　capacitance　of　the　coated　samples　annealed　under　different　temperatures　and　times　was　measured.　It　was　experimentally　shown　that　the　specific　capacitance　of　the　samples　with　BST　coating　is　greater　than　without　BST　coating.　The　composite　films　are　promising　to　be　used　as　the　dielectric　of　electrolytic　capacitor.　(C)　2004　Elsevier　Ltd　and　Techna　Group　S.r.l.　All　rights　reserved.