Objective: To investigate the effect of volume embolization ratio (VER) in evaluating the efficacy of Guglielmi detachable coil (GDC) embolization of intracranial aneurysms. Methods: A total of 434 patients with 446 saccular aneurysms (> 2 mm in diameter) were treated with GDC embolization in 7 Chinese hospitals for a period of ≥3 years and were followed up clinically and radiologically. The volume embolization ratio (VER) of aneurysm was calculated according to the ratio of volume of coils placed in an aneurysm and the volume of the aneurysm. The relationship between the VER values and the results of aneurysm embolization, the size and the neck of aneurysm, recurrence, and rebleeding were analyzed. Results: The VER of small (<5 mm), medium (5 - 10 mm), large (11 - 25 mm), and giant (>25 mm) aneurysms was (29 ± 7)%, (24 ± 7)%, (18 ± 9)%, and (8 ± 7)% respectively. The VER values had statistical significance between the patients with different sized aneurysms (F = 39.70, P < 0.01). The size of aneurysm was negatively correlated with the VER values (r = -0.50, P < 0.01). The VER values of marrow-and wide-necked aneurysms were (24 ± 8)% and (20 ± 9)% respectively, and there was statistical significance (P = 0.001). The VER of the 446 aneurysms was (24 ± 8)%. The VER in patients with complete occlusion, neck residual and partial embolization of aneurysms were (28 ± 7)%, (23 ± 7)% and (13 ± 5)%, respectively. There was statistical significance between them (F = 150.71, P < 0.01), and the degree of embolization was positively correlated with the VER values. The patients were follow-up clinically for >3 years after the procedures, and rebleeding occurred in 15 aneurysms. The aneurysmal VER in patients with and without rebleeding were (16 ± 9)% and (24 ± 8)%, respectively (P < 0.01). DSA follow-up of 357 aneurysms were obtained, the mean follow-up period was 16 months; The aneurysms in 298 aneurysms (83.5%) remained stable, its VER was (25 ± 8)%, and 59 patients (16.5%) had recurrence, its VER was (20 ± 7)% (P < 0.01). VER was the main influencing factor of rebleeding and recurrence after aneurysm embolization (OR: 0.00, 95% CI: 0.00 - 0.08; OR: 0.01, 95% CI: 0.00 - 0.03). Conclusion: VER is an objective index in evaluating the embolization of aneurysms. It has certain predicting significance for recurrence and rebleeding after aneurysm embolization.