This paper describes a grapheme-to-phoneme conversion method using phoneme connectivity and CCV conversion rules. The method consists of mainly four modules including morpheme normalization, phrase-break detection, morpheme to phoneme conversion and phoneme connectivity check. The morpheme normalization is to replace non-Korean symt)ols into standard Korean graphemes. The phrase-break detector assigns phrase breaks using part-of-speech (POS) information. In tile mort)heme-to-phoneme conversion module, each morpheme in the phrase is converted into phonetic t)atterns by looking up the morpheme phonetic pattern dictionary which contains candidate phonological changes in boundaries of the morphemes. Graphemes within a morpheme are grouped into CCV patterns and converted into phonemes by the CCV conversion rules. The phoneme connectivity table supports grarnmaticality checking of the adjacent two phonetic morphemes. In tile experiments with a cortms of 4,973 sentences, we achieved 99.9% of...