The distribution and migration of 6 kinds od β-lactam antibiotics( amoxicillin,procaine hydrochloride,cefaclor,ceftriaxone,cefotaxime,cefazolin) in municipal treatment plant were analyzed and studied in this paper by SPE-HPLC. The results showed that the contents of β-lactam antibiotics in influent and effluent were 0. 956 ~ 2. 967μg /L and 0 ~ 1. 988μg /L,respectively. The average removal rates of amoxicillin,procaine hydrochloride,cefaclor,ceftriaxone,cefotaxime,cefazolin were 100% 、34. 8% 、37. 9% 、22. 0% 、47. 8% 、63. 2%,respectively. The average removal rates of amoxicillin and cefazolin were higher than others. The main migration pathes of β-lactam antibiotics were degradation and sludge adsorption.