목적: Visual-auditory cross-modal plasticity has been widely accepted by deaf individuals. The goal of this study was to investigate the association between visual-auditory cross-modal plasticity and speech perception outcome in post-lingual deaf adult cochlear implant users by visual evoked potential response of auditory and visual cortex for visual reactivity and visual field (VF) test for spatial attention. 방법:Post-lingual deaf adults with cochlear implant (N=14) and normal adult controls (N=12) were participated in this study. The CI participants was divided into good performer group (good CI, N=7) and poor performer group (poor CI, N=7) by word perception score. All participants were analyzed with VEP response in temporal and occipital cortex. Goldmann perimetry was analyzed for identifying VF difference. The association of the amplitude of the P1 VEP response over the right temporal or occipital cortex among three groups was analyzed. In addition, the association between VF by different stimuli and word perception score was evaluated. 결과:Compared to other groups, P1 VEP amplitude in right temporal cortex was larger in the poor CI performer group, but their P1 amplitude in occipital lobe was smaller. P1 VEP amplitude in right temporal lobe was negatively correlated with speech perception outcome in the CI participants. However, P1 VEP amplitude in occipital cortex had a positive correlation with speech perception outcome in the CI participants. In VF analysis, CI users showed narrowed central VF and their extent of central VF was positively correlated with speech perception outcome. 결론:Persistent visual activation in right temporal cortex even after CI causes negative effect on outcome in post-lingual deaf adults. Insufficient intra-modal (visual) compensation by occipital cortex also causes negative effect on outcome. Based on our results of VF test, narrowed central VF could be novel behavioral evidence in CI users with poor outcome.