It has been consistently reported the deaf children have tremendous problems in reading English sentences. Three experiments were conducted in the present study to investigate the nature of deaf children's reading inability. The first experiment looked into the letter-decoding process. It was found that deaf subjects took longer than normal-hearing subjects in encoding and decoding alphabetic letters. The second experiment employed a sentence-picture verification paradigm. The results showed that deaf subjects adopted a visual-imagery coding strategy rather than a general linguistic coding strategy as described by H. H. Clark and W. Chase (Cognitive Psychology, 1972, 3, 472-517) and by P. A. Carpenter and M. A. Just (Memory and Cognition, 1975, 3, 465-473). However, when the sentence was presented in manual signs (Experiment 3), deaf subjects' verification time showed that they adopted a general linguistic coding strategy. Thus, deaf subjects are capable of linguistic coding strategy, but they do not apply it to process printed English sentences. A second-language hypothesis was advanced to account for the obtained data. Deaf children's reading inability was also discussed from this perspective.