The purpose of this study is to examine effects of language-game program utilizing fairy tails to vocabulary of children with mental retardation. A language-game program utilizing fairy tales is applied to analyze an improvement of receptive and expressive vocabulary of mentally retarded children and the use of parts of speech in terms of receptive and expressive vocabulary. To achieve this, 3 students with mental retardation who were in the special education center of K university in D metropolitan city were selected as the subjects with parental consent. The experiment using a language-game program utilizing fairy tales was held in total 20 sessions. In the intervention period, the experiment was conducted with 5 fairy tales, 4 sessions per each fairy tale, including a reading every session. In the experiment a language-game program was conducted in 4 sessions by selecting 2 categories among 8 categories per session. In order to analyze the effect of the language-game program for children with mental retardation to vocabulary improvement, the receptive and expressive vocabulary examinations were carried out by dividing a preliminary and a posthumous. The result was analyzed by presenting a raw score and an age equivalent. The result is as follows: First, a language-game program utilizing fairy tales had a positive influence on receptive vocabulary of mentally retarded children. Second, a language-game program utilizing fairy tales had a positive influence on expressive vocabulary of mentally retarded children. In conclusion, a languagegame program utilizing fairy tales had a positive influence on improvement receptive and expressive vocabulary and the frequency of parts of speech utilization in terms of receptive and expressive vocabulary of mentally retarded children.