The purposes of this investigation were as follows. 1) To investigate age differences in articulation development. 2) To investigate sex differences in articulation development. 3) To investigate the pattern of articulation errors by consonant position, developmental order, pattern of subsitutions, omitions, and distortions. 4) To determine the need for speech correction services. 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. 30 As chronological age increased, articulation errors decreased, especially between the ages of 4 and 5. 4) Distortions were the most frequently observed errors, followed by substitutions and omissions. The developmental pattern of consonants appeared to be from omission to substitution to distortion to normal articulation. 5) According to consonant position, correct production of initial consonants was achieved before correct articulation of final consonants. Correct production of medial consonants was mastered later than the other two positions. 6) The results appears to indicate that ages 4~5 ard 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.