This trial is an prospective, government-funded registration study that will observe the safety and effectiveness of intracranial stenting for preventing stroke during a mean follow-up of 12 months in patients with symptomatic stenosis of a major intracranial artery (MCA, carotid, vertebral, basilar). This trial will be launched by Xuanwu Hospital, Capital University of Medical Science, with 20 collaborators participating. Enrollment will begin in 2013, and it aims to have a sample size of 840 subjects in 2 years. The trial is scheduled to complete in 2015. As we know, SAMMPRIS is flawed with defect in design, heterogeneity in experience and credentials of operators and high rate of complication; Whether the interventional therapy for symtomatic intracranial artery stenosis is effective or not remained resolved. This trial has been modified based on SAMMPRIS in order to acquire the data for China: Technique, experience, and credential of the operators are closely related with perioperative complications in PTAS. The investigators select 50 large-scale medical centers for participation on the basis of geographical distribution. All the participants are ranked as top in China. They have the most experienced surgeons or interventionist in China, and are fully qualified for this trial. This will guarantee the success and safety of technique, maintain the continuity of operator's experience, and make the complication rate as low as possible.