This paper aims at the investigation into the grammatical characteristics of the syntactic structures with the case alternation of “-e” and “-e/ril” in the middle Korean by considering the phenomena of the case alternation with the verb types. This study can be briefly summarized as follows. First, the alternations phenomena of the “-e/ril” in the middle Korean are shown in more types of verbs as compared with the contemporary Korean. The pheonomena had been found in psych verbs, cognition verbs, thought verbs and perception verbs as well as moving verbs, attitude verbs. Second, the locative case, “-e” in the syntactic structures of psych verbs, cognition verbs, thought verbs, and perception verbs was applied to the “objective” usage in the middle Korean. The objective “-e” has gradually losed the function over time, and it can be applied to some restricted verbs including attitude verbs in the contemporary Korean. Third, for the “-e” and “-e/ril” in the syntactic structure of moving verbs, the phenomena of the case alternation in the middle Korean was shown less than that in the contemporary Korean. Fourth, for the “-e/ril” in the syntactic structure of moving verbs, the meaning of “direction” in the middle Korean was used less than that in the contemporary Korean.