Abstract: A method was separately developed for the quantitative analysis of four antibiotics (erythromycin, trobicin, azithromycin, netilmicin) in their reagent by HPCE. The linear range and recovery of these antibiotics were studied. A good reproducibility in the experiment was obtained. Compared with the traditional method, the HPCE method was not only simple and quick but also had good selectivity and reproducibility.