The purpose of this study is to investigate the effect of art therapy by means of poems in self-expression of autistic disabled persons. The subject of the study is 23-year-old male who received second grade autistic disorder. The measurement tools were K-ABCL, LMT, and DAS, and self-expression was examined through comparative analysis of pre- and post-test. The results of this study are as follows; First, in art therapy, self-expressions by language, painting, and behavior were passive in the beginning, but positive change appeared repeatedly. Second, the K-ABCL was conducted by a social worker who could observe the subjects daily. The difference between the pre- and post- test measures K-ABCL showed a positive change in the "atrophy" and "friend" parts. Third, the difference between the pre- and post- test of LMT showed that the additional configuration of the person was changed. Fourth, DAS pre- and post- test differences showed a positive change in self-expression due to the appearance of other objects in the pictures. Accordingly, it can be concluded that art therapy by means of poems as a medium has a positive effect on self-expression of autistic disabled persons.