The antibiotic residues of the urine, the liver, the lung, the kidney and the spleen in slaughtered pigs at Kyongbuk province were detected by TLC(505 kit) and EEC-4 plate method. 1. The positive rate of residual sulfamethazine which was detected by 505 kit in the urine (n=200) was 0.0%. 2. The positive rate of residual sulfamethazine which was detected by EEC-4 plate in the urine (n=126), the liver(n=98), the kidney(n=72), the spleen (n=68) and the lung(n=48) were 63%, 49%, 36%, 34% and 24%, respectively. 3. By EEC-4 plate method, the positive detection rates of the urine were 53.0% in BS(pH 6.0), 29.0% in BS(pH 7.2), 11.5% in BS(pH 8.0) and 13.0% in ML(pH 8.0) medium, that of the liver 41.5% in BS(pH 6.0), 22.0% in BS(pH 7.2), 6.5% in BS(pH 8.0) and 5.0%, in ML (pH 8.0) medium, that of the lung 21.0% in BS(pH 6.0), 9.5%, in BS(pH 7.2) and 8.5% in BS(pH 8.0) medium, and that of the kidney 31.5% in BS(pH 6.0), 14.5% in BS(pH 7.2), 20.0% in BS(pH 8.0) and 3.0% in ML(pH 8.0) medium. In the spleen, only in BS(pH 6.0) medium the positive rate was detected as 33.5 %. 4. The positive rates of samples which shown TLC-positive detected by EEC-4 plate method were 53.9% in no band, 77.8% in one band, 80.9% in two bands, 66.7% in three bands, respectively. In conclusion, the EEC-4 plate method could be applied for the detection of residual antibiotics in samples which shown as out of standard Rf values by TLC-method (SOS kit).