The　Al/Ag/Al　electric　composite　films　were　prepared　by　magnetron　sputtering　and　treated　at　480°C　due　to　the　ability　of　oxidation　resistance　of　Ag.　The　morphology　and　composite　of　Al/Ag/Al　composite　films　were　characterized　by　scanning　electron　microscope　(SEM)　and　X-ray　spectroscope　(EDS),　respectively.　The　results　indicated　the　surface　of　composite　films　was　oxidized　in　the　process　of　heat　treatment.　The　Ag-Al　alloy　with　rich　Ag　and　Ag3Al　compound　were　produced　for　the　interdiffusion　between　Ag　and　Al　atoms　during　the　magnetron　sputtering　and　heat　treating.　The　resistivity　of　Al/Ag/Al　composite　films　was　largened　as　a　result　of　an　Al　layer　at　the　surface,　and　which　was　about　19.4×10-6Ω·cm　after　heat　treatment.