Abstract: OBJECTIVE To provide rational medication reference advice for patients by summaring the clinical practice of clinical pharmacists participating in a case of meropenem combined with valproic acid after craniocerebral operation. METHODS Clinical pharmacists analyzed the case in which there was a combination of meropenem and valproic acid after craniocerebral operation that led to decrease the serum concentration of valproic acid significantly, and proposed the serum concentration monitoring and medication suggestion, then provided medication reference for similar cases as follows through literatures review. RESULTS & CONCLUSION The combination of carbapenems and valproic acid may lead to decrease the serum concentration of valproic acid significantly, clinical pharmacists advised to adjust antiepileptic drugs, anti-infective drugs or strengthen monitoring patients in clinical to obtain the good treatment effect.