This investigation is concerned with the development of articulation skills in children aged three to six years. The subjects were randomly selected from 430 children enrolled in four day care nursery schools in Daegu. An articulation evaluation for 19 Korean consonants was administered to 239 children (124 boys, 115 girls). The results of this investigation were as follows. 1) There was no significant difference in consonant errors between ratings by 9 nursery school teachers and the author. 2) There was no significant difference in articulation scores between boys and girls. 3) As chronological age increased, articulation errors decreased, especially between the ages of 4 and 5. 4) Correct articulation of nasal consonants was achieved before production of fricatives. Most fricatives were found to develop between the age of 3 and 4, while other consonant types appeared to develop between the ages 4 and 5. 5) Correct articulation of bilabial & glottal consonant was achieved before 3 years of age, but palatal consonants were not developed until after 5 years of age. 6) There was a tendency to be substituated for nasal (bilabial) and same kinds of consonants. 7) The results appear to indicate that ages 4~5 are important in the development of articulation skills. Conclusions indicate that children presenting with articulation errors after age five, may not spontaneously develop normal articulation and should be considered for speech correction services.