The incorporation of the nominative particle -i and copula -i- into a low-pitched syllable of nouns produces a rising tone in the Middle Korean. The volitive -o/u- and adverbative suffix -i also cause the same morphophonemic change. The rising tone is the result of contraction of an even tone and a departing tone. There are two conditions for the rising tone by contraction. First, even tone must be linked to syllabic in the contraction. In addition, if the noun had a departing tone within a word, this morphophonemic change would not occur. However, compound is the exception for the second condition. Compound is same with phrase in terms of tonal changes in the Middle Korean. This condition suggest that only first high-pitched syllable is distinctive in Middle Korean.