The purpose of this study was to examine the development of generative naming ability for 112 normal Korean children aged 3, 4, 5 and 6 years. In this study, we investigated how naming ability is developed through clustering and switching; these are the criteria for quantitative and qualitative analysis of words produced by children of this age group, since they show an explosive development of their vocabulary. The following results were obtained: 1. With increasing age, the total number of words produced was significantly increased according to generative naming ability, as was measured with a semantic fluency test and a phonemic fluency test. 2. With increasing age, semantic and phonemic fluency tests contained within the generative naming test showed significant increases for the frequency of clustering and switching. 3. In the semantic fluency test, boys performed better than girls in the ‘animals’category, whereas girls came up with significantly more words in the ‘items in stores’category. 4. In the phonemic fluency test, a significant correlation was shown by these age groups for reading ability and word production. This correlation was very significant for younger children whose reading ability was individually different. 5. As the frequency of phonemes was high, as provided in the generative naming according to the phonemic fluency test, so the number of words produced was also high. These results showed that generative naming ability is increased significantly in preschool age children, i. e., 3, 4, 5 and 6-year-old children. This increase is due to the use of clustering and switching. Generative naming according to a phonemic fluency test showed a significant correlation in reading ability and the extent of word production. Thus, the phonemic fluency test of the generative naming test is needed for children at the age when reading abilities are equalized.