To evaluate the auditory performance of infants with cochlear implants at the early stage after surgery, summarize the development of auditory ability, investigate the effect of age at cochlear implantation on auditory performance within the first year after surgery and provide a reference for their habilitation program. A total of 272 infants with prelingually profound hearing loss participated in this study, ranging in age at cochlear implantation from 18 to 36 months. The mean age was 21 months with a standard deviation of 7 months. Infants with cochlear implants were divided into three groups according to their age at implantation. Infants in group A were implanted under 18 months of age. Infants in group B were implanted between 18 and 24 months of age. Infants in group C were implanted between 25 and 36 months of age. Categories of auditory performance (CAP) was used to evaluate the auditory performance, which rates auditory abilities in eight categories for a scale of 0 to 7. The mean scores of CAP for all infants at each interval were significantly different after implantation. Significant differences were observed in mean scores of CAP among these three groups in 1 and 3 months after switch-on. However there were no significant differences in pre-operation, 6, 9 and 12 months after switch-on. There is a significant improvement in auditory performance of infants with prelingually profound hearing loss within the first year after cochlear implantation. The age at cochlear implantation has no critical influence on the development of auditory capabilities at the early stage after surgery. CAP is a practical tool which can be used in clinic in China.