Objective To investigate the effects of antiepileptic drugs (AEDs) with warfarin functions and blood coagulation system, to provide the reference for clinicians of the selection of AEDs under the combination therapy with warfarin. Methods Analyse the clinical data of the patient with symptomatic epilepsy from the Second Clinical Medical College of Guiyang University of Chinese Medicine on April 1, 2017, whom taking AEDs and warfarin at the same time, clear the drug adverse reactions, and analysed related literature. Results After the treatment with valproate, abnormal blood coagulation, a danger and emergency data appeared, so we stopped using warfarin immediately, and reduce the dosage of valproate gradually, insteadly, we used levetiracetam as antiepileptic therapy. Monitoring blood coagulation function, when it returned to normal, restart warfarin anticoagulant therapy. Conclusions When start antiepileptic treatment in relevant basic diseases of symptomatic epilepsy, for a variety of combination reactions, AEDs can affect the anticoagulant effect of warfarin, so we need to consider the interaction between drugs and avoid adverse reactions.