The Korean National Residue Program consists of three sampling plans for domestic and imported foods of animal origin : monitoring, surveillance/enforcement and exploratory testing. Monitoring and surveillance/enforcement testing programs are routinely implemented by 17 Provincial Veterinary Services for domestic products and two regional offices of Animal, Plant and Fisheries Quarantine and Inspection Agency (QIA) for imported products, respectively. The exploratory testing is designed to test substances which are not included in the list of monitoring and enforcement testing programs controlled by headquarter of QIA. In 2010, the exploratory testing was carried out in domestic and imported foods of animal origin for 24 veterinary drugs including florfenicol, clavulanic acid, four quinolones (nalidixic acid, difloxacin, marbofloxacin, orbifloxacin), two anthelmintics (closantel, levamisole), two sedatives (azaperone, carazolol), six glucocorticoids (dexamethasone, betamethasone, flumethasone, prednisone, prednisolone, methylprednisolone), eight non-steroidal anti-inflammatory drugs (phenylbutazone, paracetamol, carprofen, flunixin, ketoprofen, meloxicam, tolfenamic acid, acetylsalicylic acid). In the total of 1,153 domestic samples, only florfenicol was detected from 17 pig muscles at levels of 0.2～614 ng/g. Of 17 positive pig muscles, 16 samples were non-violative and one sample was violative. In the total of 1,065 imported samples, florfenicol was detected at 0.4 ng/g in one pork. Also, flunixin was detected at 22 ng/g in one beef.