Introduction: Patients with symptomatic high-grade intracranial atherosclerotic disease (ICAD) are at risk of stroke recurrence even under stringent medical therapy. Understanding how the plaque evolves in these patients may help prevent recurrent stroke. Methods: In a prospective, multicenter referral, longitudinal study, we recruited 40 patients (mean age = 61.1 years) with symptomatic high-grade ICAD (70-99% stenosis) confirmed by 3-dimensional rotational angiography (3DRA) from July 2007 to Feb 2016. All patients had 3DRA at baseline and 1 year. All patients received contemporary optimal medical treatment. We assessed the morphological features of qualifying ICAD lesions in the paired 3DRA images. A plaque was considered progressive if the plaque surface evolved from being smooth to irregular/ulcerated or from irregular to ulcerated, or the affected artery occluded at 1 year. We explored factors associated with plaque progression. Results: The qualifying ICAD lesions were in average 77.7% stenosis at baseline. The point of maximum stenosis was located at the distal end of the plaques in 21 (52.5%) cases, and 38 (95.0%) patients had eccentric plaques at baseline. The mean upstream plaque shoulder angulation was 46.4° at baseline. Eleven (27.5%) ICAD lesions progressed from baseline to 1 year. Longer lesions (p=0.038) with a smaller upstream plaque shoulder angulation (p=0.038) and the maximum stenosis locating at the distal end of the lesion (p=0.056) at baseline were more likely to progress in the plaque morphology over 1 year. Conclusions: Under modern medical treatment, although the majority of symptomatic ICAD lesions might regress over 1 year after an index stroke, lesions of a longer length, a smaller upstream angulation, or with the maximum stenosis located at the distal end were more likely to progress in terms of the plaque morphology.