Cefoselis is a widely used antibiotic of β-lactam . Cefoselis has a large antibacterial spectrum against gram positive bacterium. It is a 4th generation of cephalosporin. Cefoselis has some side effects, such as inducing seizures and convulsion in elder and renal failure patients. Through testing the dialysate and blood samples by HPLC, it shows that cefoselis appears in the striatal dialysate samples does-dependently and disappears rapidly from the extracellular fluid. In renal failure rats, the elimination half-lives of cefoselis are prolonged. It may be one factor of the seizures caused by cefoselis. In addition, administration of cefoselis into the hippocampus causes highly increase of extracellular glutamate and slightly increase of GABA, suggesting that cefoselis induces seizures through blocking the GABA receptors .