Objective To explore the effects of wearing ankle-foot orthoses (AFOs) on motor function in children with spastic cerebral palsy (SCP). Methods Fifty-two children with SCP were randomly divided into a wearing-for-training group (n = 16, group 1 ), a day-wearing group (n = 19, group 2) and a day-night-wearing group (n = 17, group 3). In addition to the conventional rehabilitative treatment given to all participants, the children in group 1 wore AFOs during movement training, and children in group 2 wore AFOs in the daytime for 6-8 h per day, while AFOs were applied to the children in group 3 for 24 hours a day except for cleaning and during certain training routines. All the treatments were continued for 2 months. Clinical assessments included the range of passive ankle dorsi-and plantarflexion (APROM) , modified Ashworth scale (MAS) ratings, and the D and E dimensions of the Gross Motor Function Measure (GMFM). All were performed before and after treatment. Results Before treat-ment, no statistically significant differences were found among the three groups in terms of APROM, MAS, or GM-FM. There were significant subsequent improvements in groups 2 and 3 when compared with group 1 in terms of APROM, MAS and GMFM results. Group 2's improvements in APROM and MAS results were not significantly better than those of group 3, but their average GMFM score improvements were significantly better. Conclusion Wearing AFOs in the daytime 6-8 hours per day is more effective in reducing spasticity and improving functional performance in children with SCP.