The purpose of the present study was to examine the method and the possibility of teaching moderately mentally retarded (MR) children to read Japanese syllabic characters (Kanamoji) through the formation of the act of analyzing the syllabic structure of words (ASSW). In experiment 1, which aimed at ascertaining the development of coordination and its relation to the acquisition of the act of ASSW, the following tasks were given to 6 to 12-year-old moderately MR and 3-4 year-old normal children. Tasks: 1) a reading test of kana-moji, 2) an articulation test, 3) the task of articulating and separating words into-syllables, 4) the task of clapping hands rhythmically coordinating with a series of pulses, 5) the tasks of moving hands in reciprocal coordination, 6) the tasks of pronouncing syllables of given words one at a time in sequence at intervals of 0.3, 1.0 and 2.0 sec. As results, the following facts were ascertained: 1) MR children's insufficient ability of ASSW proved to be related to poor coordinate function and articulatory disorders. 2) Although even a child with extremely poor coordinate function and with severe disorder in articulation was found to be able to articulate syllables of a word in sequence coresponding one to one to hand claps, as long as the syllabic structure of the word was simple such as mama, papa, momo (a peach) 3) Children who had not acquired the act of ASSW, proved to be unable to pronounce each syllable of the words aloud in sequence at longer interval (2.0 sec.) without the help of vocal-coordinating motor acts. 4) The main determinant of dfficulty of the tasks of separating a word into syllables, was found to be the length of the pause between syllables pronounced. This experiment brought us the following hypothesis: Learning to separate words into syllables in the tasks which demand the longer interval, will not only make a child separate words more precisely, but also cause him to pay voluntary attention to the syllabic components of words. Experiment 2: Bassed on these facts and hypothesis, the following 4 steps training program was constructed for moderately MR children in preparation to the formation of the act of ASSW. 1) A child learns to separate the words into syllables, clapping his hands. 2) He learns to separate the words into syllables, jumping into circles one after another. 3) He learns to syllabify the words, putting small wooden dolls on bases placed at 10cm intervals, pronouncing one syllable for each doll. Then the intervals are made gradually longer; 30cm, 50 cm, 1m, 2m. Then he learns to abstruct the first and/or last syllable of words. 4) He learns to construct a word, putting small wooden kana-blocksone at a time on the same characters below the picture of the word, pronuncing the syllable. And 3 steps training program was prepared to teach them to read and construct words in Kanamoji. According to these programs, nineteen moderately MR school children from 6 to 12 years old, who had no knowledge of kana-moji and had not yet acquired the act of ASSW, were trained individually and/or in small groups. As a result, most MR children (9 out of 11) with no deficiency in speech proved to be able to learn the act of ASSW. And as for children with severe speech deficiency, 3 out of 8 children had acquired this act in training period. Out of 11 children who acquired the act of ASSW, eight underwent the training of Kanamoji. As a result, most of them (7 out of 8) showed rapid progress in learning to read Kanamoji. These experiments suggest the high possibility of teaching MR children to read Kanamoji under the condition of elaborated training program.