The phenomena of dc electrical degradation of (Ba0.5Sr0.5)TiO3 thin films was studied. From our experimental and analytical results of current versus voltage (I-V) characteristics, it was shown that the degraded devices exhibited analogous leakage behavior with the devices which have thin intercalated (Ba0.5Sr0.5)TiO3 layers with intentionally introduced oxygen vacancies between cathodes and thick (Ba0.5Sr0.5)TiO3 layers without intentionally introduced oxygen vacancies. This could be explained by assuming that oxygen vacancies accumulate at the interfaces between the cathodes and the (Ba0.5Sr0.5)TiO3 films after fatigue.