Purpose: to evaluate the functional result and complications of silicon frontalis sling to correct congenital ptosis with poor levator function in children. Methods: prospective clinical interventional study on 37 eyelids of 30 patients under 7 years old. Result: follow-up 1-16 months (mean 6.13 + or - 5.9). Seven patients had bilateral and 23 unilateral surgeries. The cosmetic outcomes, marginal reflex distance (MRD) and recurrence rate were evaluated In all patients, MRD increase an average of + 2.23 mm after the operation. The cosmetic results: Excellent 10 patients (33.3 percent), good 15 patients (50 percent), poor 5 (16.7 percent) in bilateral group. Excellent result 8/23 (34.78 percent), good 11/23 (47.83 percent) and poor 4/23 (17.39 percent). Extrusion of the sling node with infection occurred in 1 patient, without infection in 1. The recurrence of the ptosis occurred in 2 patients due to the silicon rod breakingjust in 1 week postoperation. Conclusion: silicon rod is an effective material in frontalis suspension for the treatment of congenital ptosis with poor levator function in children to prevent secondary amblyopia due to occlusion of visual axis.