Objective:To observe the clinical effect of helmet therapy in cranial remodeling of infants with deformational plagiocephaly.Methods:A total of 114 infants with plagiocephaly received helmet therapy at the age of 4 to 12 months over the period from 2016 to 2018 and the results were analyzed retrospectively. Seventy-four were male and forty female. The average ages were (7.49±1.91) and (7.54±2.10) months, respectively. A Spectra scanner was used to quantify each head′s radial symmetry index (RSI), cranial vault asymmetry (CVA) and cranial vault asymmetry index (CVAI) before and after 100 days of treatment, and those data were related with age (4-6 months, 7-9 months and 10-12 months), gender and severity of deformity (levels III-V).Results:The average RSI, CVA and CVAI improved significantly for all of the infants studied. The average RSI, CVA and CVAI improved the most for those 4-6 months old. Those with level-IV deformity showed significantly better improvement than those with level III or V deformity.Conclusions:Helmet therapy is an effective way to improve deformities due to plagiocephaly among infants. The best age for treatment is 4-6 months. Patients with less malformation are more easily corrected.