This prospective, multicenter trail will be conducted in China. Based on the previous work,participants will be divided into two groups :symtomatic ICAD and asymtomatic ICAD. Neurological examination and clinical sera testing will be performed at baseline, 1 month, 3 months, 6 months, and 12 months.The stroke incidence rate of asymptomatic ICAD and stroke recurrence rate of symptomatic ICAD will be recorded.