Abstract: Objective To detect patients with intracranial and extracranial artery stenosis with thrombelastograph (TEG), find the best time of taking drugs and provide reference for the surgery. Methods Two hundred and fifty-five patients admitted to Chinese PLA General Hospital from December 2012 to December 2014 who would undergo stenting were included in this study. They were divided into two groups, patients who hadn't taken aspirin and clopidogrel previously served as group A (n=146), and patients who had taken aspirin and clopidogrel for more than one week served as group B (n=109). Patients in these two groups took 100mg of aspirin and 75mg of clopidogrel on the day of admission. Platelet inhibition ratio induced by arachidonic acid (AA) and adenosine diphosphate (ADP) on 1 d, 3 d, 5 d, 7 d after taking drugs was detected by thrombelastograph. Results There was no significant difference in AA- and ADP-induced platelet inhibition ratios when compared 1 d with 3 d (P> 0.05), while it showed significant difference in AA- and ADP-induced platelet inhibition ratios when compared 1d with 5d in group A (P< 0.05). The AA- and ADP-induced platelet inhibition ratio on 1 d were (70.43±15.32)% and (36.52±19.38)%, respectively, which showed a good level of inhibition after patients taking the medicine for only one day after hospitalization, while it had no significant difference when compared with 3 d, 5 d, 7 d (P> 0.05). Conclusion If patients take aspirin and clopidogrel for more than 5 days before stenting without taking them previously, it can achieve a better platelet inhibition effect. Patients taking aspirin and clopidogrel for over 1 week before hospitalization will achieve a better platelet inhibition effect by taking them on 1d after hospitalization. TEG can provide references in stents treatment time for patients with intracranial and extracranial artery stenosis during stenting.