This study selected 30 postlingually deafened patients underwent elective surgery for cochlear implantation. As , the intra-operative electrically Evoked Stapedius Reflex Threshold ( ESRT) depends greatly on the selective anesthesia and this threshold could be used as the upper limit in speech processor adjustment for infant ,so the patients were divided randomly into two equal groups according to the type of anesthetic drug used : isoflurane and propofol. The intra-operative (ESRT) was closely related to the post-operative T-level and MCL level during propofol anesthesia in contrast to isoflurane anesthesia.