The purpose of this study was to analyze the relationship between segmental correctness and speech intelligibility in adults with hearing impairment. Segmental correctness was measured by percentage of correct vowels(PCV) and percentage of correct consonants(PCC). The results were shown as follows: First, PCV and PCC could predict speech intelligibility with statistical significance. Second, in consonant classes divided by place and manner of articulation, the PCC of plosives and alveolar sounds were significant predicting variables in each group ($R^{2}=50%;;59%$). According to this study, the importance of segmental correctness on speech intelligibility of adults with hearing impairment was confirmed. Also correctness of plosive sounds in manner and alveolar sounds in place were significant factors to speech intelligibility.