This paper tries to explore the language acquisition of 3-to 5-year old children, especially in the field of phonology. Based upon this, the aim of his study is to raise the fact based on the data collected. Therefore, this paper can be categorized into the type of descriptive qualitative research. By this consideration, the data collecting technique used in this study is participatory conversational observation combined with informal technique as the data presentation technique so that the final presentation of the data will be specified into the description of the data that have been analyzed. Hence, the result of this study that can be raised to the surface is that 3-to 5-year-old children in kindergarten "Buah Hati" Rembiga are still problematic in pronouncing all sounds belonging to the plosive and fricative.