A sensitive method for simultaneously determining residues of tetracyclines oxytetracycline, tetracycline and chlortetracycline in animal muscle tissues was established by reversed _ phase high performance liquid chromatography with solid phase extraction. The experimental conditions were optimized. Under the selected conditions the detection limits were 20 μg/kg, 40 μg/kg and 100 μg/kg for oxytetracycline, tetracycline and chlortetracycline, respectively. The RSDs of 5.1%~7.1%(n=5) and average recoveries of 80%~82% were obtained for them.