Classification (According their structures) 1Beta- Lactam antibiotics(β-内酰胺类) 2 Tetracylines antibiotics(四环素类) 3 Aminoglycoside antibiotics(氨基糖甙类) 4 Macrolides antibiotics(大环内酯类) 5. OthersClassification (According their structures)： 1.Beta-Lactam antibiotics (β –内酰胺类) 2.Tetracylines antibiotics (四环素类) 3.Aminoglycoside antibiotics (氨基糖甙类) 4.Macrolides antibiotics (大环内酯类) 5. Others