Objective To investigate the correlation between CYP2C19 gene polymorphism and clopidogrel resistance(CR)in patients with ischemic stroke in the north of China.Methods The patients with ischemic stroke were selected as the research object from the First Hospital of Hohhot during September 2015 to No-vember 2016.The polymorphism of CYP2C19 gene was detected by Taqman probe method.Results The clo-pidogrel resistance ratio of the study population is 59%.There is a strong correlation between the CYP2C19* 2 mutant strains with clopidogrel resistance(P=0.006),and we foundd that the increased glutamic oxala-cetic transaminase was associated with clopidogrel resistance.Conclusion Patients with the CYP2C19*2 al-lele were at greater risk of clopidogrel resistance during antithrombotic therapy.