With the introduction of polycone cochlear implants and confirmation of their effectiveness, the FDA approved cochlear implants for children with prespeech deafness in 1990 and further relaxed the age of implantation for children from 2 years of age and older to 12 months in 2000. The 2003 edition of our cochlear implant guidelines also set the optimal age for implantation at 12 months to 5 years of age. Recently, cochlear implantation has become a hot topic of discussion in infancy or under 12 months of age. Based on the sensitive period of auditory development and the maturity of the implantation technique, it is recommended that cochlear implantation be performed as early as possible so that the child can receive early auditory stimulation and promote the development of the speech center. The results of domestic and international studies have confirmed that cochlear implantation before the age of 1 year is significantly more effective than implantation after the age of 1 year. However, the lower age limit for cochlear implantation should be as early as possible if systemic conditions allow, usually after 6 months of age.