To investigate the hearing and speech rehabilitation results of cochlear implantation in patients with common cavity deformity.A retrospective study was performed on 19 patients with common cavity deformity who received multi-channel cochlear implantation from 1995 to 2010 in Peking Union Hospital, with assisted evaluation of auditory nerve pathways by intraoperative electrical evoked auditory brain stem response (EABR); matched with 19 implantees with no deformity. Paired T test was performed to compare T values, dynamic range; Rank-sum test was performed to compare scores of categories of auditory performance (CAP) and speech intelligibility rating (SIR).The T value of common cavity inner ear malformation group (172.59 +/- 14.57) was significantly higher than that of the control group (139.63 +/- 19.45) (P 0.05); hearing and speech rehabilitation after implantation showed that the results of CAP and SIR values (5.50 +/- 0.94 and 3.00 +/- 0.82) scored significantly lower than the control group (6.90 +/- 0.77 and 3.90 +/- 0. 57) (P < 0.05), but significantly increased compared with that before. Some children appeared facial twitch at boot time caused by electrical stimulation of the facial nerve (surface pumping rate of 31.58%).Common cavity is a kind of severe inner ear malformations, but to perform a comprehensive preoperative evaluation, select the appropriate surgical technique, employ personalized postoperative booting, transfer machines and long-term auditory intensive language training, the children can get varying degrees of language and hearing recovery according to the severity of deformity. On the whole, the rehabilitation outcome was significantly worse in patient with deformity than its counterpart without deformity.