This paper was a single‐subject experiment study to clarifying the effect of nursery rhyme activities on elementary underachievers’ dictation ability, and its research questions are as follows. First, what effects do nursery rhyme activities have on underachievers’ spelling? Second, what effects do nursery rhyme activities have on underachievers’ word spacing? To answer these questions, we selected 3 first‐grade underachievers at B Elementary School in Daegu and conducted the experiment for 6 weeks, 4 sessions per week and a total of 20 sessions, and 40 minutes per session. The program was composed of 18 nursery rhymes selected from the nursery rhyme programs of Choi In-sil(2002) and Shin Jae-choong(2004) and nursery rhymes in the ‘Pleasant Life’ textbook for the 1st graders. The evaluation tool, which contained 10 questions for each session, was prepared by the researcher in a way that children could read, write and understand easily the words of the nursery rhymes modified in consideration of adequacy for spelling and word spacing and through consultation with the impression of the researcher and the subjects. The conclusions obtained from the results and discussion of this study are as follows: First, nursery rhyme activities were effective in improving the underachievers’ spelling ability. As the words were oriented to children and easy to sing, the underachievers could approach nursery rhymes with interest and learned vocabulary naturally in the process of singing nursery rhymes and this was considered to improve their spelling ability. Second, nursery rhyme activities were effective in improving the underachievers’ word spacing ability. As the underachievers sang their favorite nursery rhymes repeatedly their interest in and concentration on learning were heightened, and as a result they came to pay attention to what the teacher was saying in the dictation test and this was considered to improve their word spacing ability. Key Words : Nursery Rhyme Activities, Underachiever, Dictation Ability, Spelling Ability, Word Spacing Ability