This study was carried out to compare the antibiotic residues in the muscles of cattle and pigs from slaughter-houses in Seoul from 2000 to 2002 by EEC-4-plate, Charm II and HPLC methods. The results were summarized as follows; 1. Residual materials were detected from 41 samples(0.6%) by EEC-4-plate method from random sampling and 38 samples(12%) by Charm II method from directed sampling. 2. Violation rates were 0.3% by monitoring and 4.7% by surveillance program. 3. The 35 samples were classified as tetracyclines 30(86%), sulfonamides 4(11%), ${eta}$-lactams 1(3%) and two samples simultaneously determined oxyteracycline plus sulfadimetoxine, and sulfamerazine plus sulfadimetoxine. 4. The highest residual concentration(ppm) of chlortetracycline, oxytetracyline, sulfamethazine, sufadimetoxine and penicillin were 0.5, 12.0, 6.4, 2.6 and 0.44, respectively.